Standardized metrological characteristics of indicator tubes and air intake devices for them
Read also
This standard establishes an accelerated method for measuring the concentrations of harmful substances in the air. working area indicator tubes, except for underground mine air.
| Designation: | GOST 12.1.014-84* |
| Russian name: | SSBT. Work area air. Method for measuring concentrations of harmful substances using indicator tubes |
| Status: | current Reissue (April 2001) |
| Replaces: | GOST 12.1.014-79 |
| Date of text update: | 01.01.2009 |
| Date added to the database: | 10.11.2009 |
| Effective date: | 01.01.1986 |
| Approved: | State Standard of the USSR (12/14/1984) |
| Published: | IPC Standards Publishing House No. 2001 Publishing house of standards No. 1988 |
STATE STANDARD OF THE USSR UNION
System of occupational safety standards
Work area air
Method for measuring concentrations of harmful substances
indicator tubes
GOST 12.1.014-84
MOSCOW
APPROVED AND ENTERED INTO EFFECT by Resolution State Committee USSR according to standards of December 14, 1984. No. 4362
INSTEAD GOST 12.1.014-79
The validity period was lifted by decision of the Interstate Council for Standardization, Metrology and Certification (Protocol No. 5-94)
REISSUE (January 1996) with Change No. 1, approved in March 1990 (IUS 7-90)
This standard establishes an accelerated method for measuring concentrations of harmful substances in the air of a working area using indicator tubes, except for the air of underground mines.
The essence of the method is to change the color of the indicator powder as a result of a reaction with a harmful substance (gas or steam) in the analyzed air sucked through a tube. Concentration measurement harmful substance is made according to the length of the layer of indicator powder in the tube that has changed its original color (linear-coloristic indicator tube) or according to its intensity (colorimetric indicator tube).
The terms used in the standard and their explanations are given in the Appendix.
The characteristics of the produced indicator powders are given in the Appendix.
The standardized metrological characteristics of indicator tubes and air intake devices for them are given in the Appendix.
STATE STANDARD OF THE USSR UNION
| Occupational Safety Standards System Work area air Method for measuring concentrations of harmful substances indicator tubes Occupational safety standards system. | GOST In return |
Date of introduction1986-01-01
1. EQUIPMENT
1.1. Indicator tubes, including those equipped by the consumer using special kits with syndicator powders.
1.2. Filter tubes, including those equipped by the consumer using special kits.
1.3. An air intake device (such as a pump, bellows, etc.) designed for use with this indicator tube.
2. PREPARATION FOR MEASUREMENT
2.1. Preparation of equipment for measuring concentrations of harmful substances in the air of the working area is carried out in accordance with the regulatory documentation for indicator and filter tubes and the air intake device intended for them.
2.2. In untested production conditions, before carrying out measurements with indicator tubes, it is necessary to conduct a one-time qualitative assessment of the composition of the air in the working area using certified methods or methodological instructions,approved by the Ministry health care of the USSR. Based on the data obtained, the possibility of using indicator tubes for planned or operational control. Regardless of the composition of the air in the working area, the use of filter tubes with indicator tubes, if provided for in the regulatory documentation for indicator tubes, is mandatory in order to avoid violation of the operating conditions of the indicator tubes.
A repeated qualitative assessment of the composition of the air in the working area should be carried out with each change in production technology that may cause the appearance of air environment new harmful substances.
2.1, 2.2 (Changed edition, Amendment No. 1).
3. MEASUREMENT
barometric pressure - from 90 to 104 kPa (680-780 mm Hg);
relative humidity - 30- 80 %;
temperature - from 288 to 303K.
Deviations from the specified parameters are allowed if this is provided for in the regulatory and technical documentation for the measuring instruments.
Monitoring the metrological parameters of the air in the working area should be carried out in parallel with measuring the concentrations of harmful substances using indicator tubes.
3.2. An indicator tube designed to measure the concentration of a harmful substance and filter tubes, if provided for by regulatory documentation, are connected to the air intake device.
Measurement should begin no later than 1 minute after depressurization of the tubes.
3.1, 3.2 (Changed edition, Amendment No. 1).
3.3. The amount of air sucked through the indicator tubes is set in accordance with the regulatory documentation for these tubes.
Concentration ( WITH n) under normal conditions in mg/m3 is calculated using the formula
where is the result of measuring the concentration of a harmful substance at ambient temperature, t°C, relative humidity φ% and atmospheric pressure R kPa, mg/m3;
K IN - coefficient taking into account the influence of temperature and humidity of the surrounding air on the readings of indicator tubes, the value of which is determined in accordance with paragraph of the appendix.
The relative measurement error (δ) should not exceed ±35% in the range up to 2.0 maximum permissible concentrations (MPC), inclusive, and ±25% at concentrations above 2.0 MAC under the conditions specified in clause .
The measurement result is presented as: ( WITH N ± Δ) mg/m 3 confidence level 0.95.
The magnitude of the absolute errorDcalculated by the formula
In the range up to 1.0 MPC inclusive, an increase in error of up to ±60% is allowed. This is the meaning relative error must be indicated in the regulatory and technical documentation for measuring instruments.
(Changed edition, Amendment No. 1).
4. SAFETY REQUIREMENTS
4.1. When measuring the concentrations of harmful substances with indicator tubes in the air of the working area, you must comply with the safety standards and regulations in force at the given production site.
4.2. Measurement of concentrations of harmful substances with indicator tubes is carried out by persons who have been trained and authorized to work on monitoring harmful substances in the air of the working area.
4.3. When opening tubes, it is necessary to observe all safety precautions when working with glass, using special devices and protective equipment.
APPLICATION
1
Information
TERMS USED IN THE STANDARD AND THEIR EXPLANATIONS
| Explanation |
|
| Work zone | According to GOST 12.1.005-88 |
| Method for measuring the concentration of harmful substances | According to GOST 16263-70 |
| Harmful substance | According to GOST 12.1.007-76 |
| Maximum permissible concentrations of harmful substances in the air of the working area | According to GOST 12.1.005-88 |
| Indicator tube | Primary measuring transducer, structurally consisting of a glass tube filled with granular filler (indicator powder) |
| Linear color indicator tube | An indicator tube that allows you to measure the concentration of a harmful substance in the analyzed air sucked through the tube along the length of the layer of indicator powder in the tube that has changed its original color |
| Colorimetric indicator tube | An indicator tube that allows one to judge the presence of a harmful substance in the analyzed air sucked through the tube, in a concentration greater than the response concentration for a given indicator tube, by the color intensity of the indicator powder by comparison with control sample indication effect |
| Filter tube | Glass tube, filled with one or more absorbers that serve to capture gases and vapors that interfere with the measurement of harmful substances |
| Indicator powder | A granular chemisorbent that changes color when a directly detectable harmful substance or its volatile products of interaction with the chemisorbent in the filter tube passes through it |
| Absorber | A granular sorbent or chemisorbent that completely transmits the harmful substance being determined and traps accompanying substances that interfere with the analysis |
| Reading range | The range of values of the indicator tube scale, limited by the final and initial values scales |
| Lower (upper) limit | The smallest (highest) value of the measured concentrations |
| Air intake device | Device for sucking air through indicator tubes |
(Changed edition, Amendment No. 1).
APPLICATION
2
Information
CHARACTERISTICS OF PRODUCED INDICATOR POWDERS FOR EQUIPING INDICATOR TUBES
| Determined gas (steam) | Air volume sucked in, cm 3 | Measuring range, mg/m 3 | Total time air suction, with | Gas (steam) captured by the filter cartridge | Gas (steam) interfering with determination |
| Nitrogen oxides | Halogens (chlorine, bromine, iodine), ozone in concentrations above 10 MAC |
||||
| Vapors of acids, alkalis and amines |
|||||
| Sulfur dioxide | Hydrogen sulfide, ammonia, nitrogen dioxide, sulfuric acid mist, water vapor | ||||
| Acetylene | Hydrogen sulfide, hydrogen phosphide, silicon hydrogen, ammonia, acetone and water vapor | ||||
| Sulfur dioxide, vapor acetic acid, acetic anhydride, of hydrochloric acid, in concentrations up to 10 MPC | Ketone pairs and esters, vapors of acetic acid, acetic anhydride, hydrochloric acid and sulfurous anhydride in concentrations above 10 MAC |
||||
| Aromatic and unsaturated hydrocarbons, water vapor | |||||
| 400´ 3 | 360´ 3 | Water vapor | |||
| Water vapor | Fatty and aromatic hydrocarbon vapors |
||||
| Hydrogen sulfide | Mercaptans |
||||
| Water vapor | Fatty and aromatic hydrocarbon vapors |
||||
| Petroleum hydrocarbons | Unsaturated and aromatic hydrocarbons, water vapor | ||||
| Carbon oxide | Acetylene, ethylene, methane, a mixture of butane and propane, nitrogen oxides, chlorine, sulfur dioxide, hydrogen, gasoline vapors, benzene and its homologues, water, acetone, formic acid, formaldehyde, ethyl and methyl alcohols, dichloroethane, carbon disulfide | Metal carbonyl vapors |
|||
| Vapors of bromine, iodine, oxidizing agents, chloramines range of measured concentrations, main error relative error, influence functions caused by a change in an influencing quantity within operating conditions. 1.2. The characteristics of indicator tubes designed to determine the presence of harmful substances in the air of the working area (colorimetric indicator tubes) are: nominal value of the concentration of a harmful substance causing the appearance of an indication effect (activation concentration); operation error. 1.3. The following metrological characteristics are established for air intake devices: volume of sucked air, error in dosing the volume of sucked air. Instead of volume, it is permissible to normalize the duration of suction and the volumetric flow rate of air sucked through the indicator tube. 2. Standardization methods and forms of presentation of metrological characteristics 2.1. The nominal static conversion characteristic is presented in the form of a formula or graph, which corresponds to a scale printed on an indicator tube, cassette or special label. 2.2. The range of measured concentrations is characterized by its lower and upper boundaries. The lower limit of the measurement range should be no more than 0.5 maximum permissible concentration, and the upper limit - no less than 5 maximum permissible concentrations for a given substance. It is possible to divide the measurement range into several subranges by changing the volume of air sucked through the indicator tube, setting a nominal static conversion characteristic for each of these volumes. If the reading range does not coincide with the measurement range, then the reading range is normalized by setting the initial and final scale values. 2.3. The main error of indicator tubes is characterized by the limit of the permissible main error. The values of the limit of the permissible main error must be selected from the series established in GOST 8.401-80. At the stages of development of indicator tubes, their main error is characterized by: the limit of the permissible value of the systematic component of the main error, the limit of the permissible value of the standard deviation of the random component of the main error. 2.4. The number of sequentially used indicator tubes, ensuring a reduction in the error of the result of measuring the concentrations of a harmful substance to values not exceeding those established in paragraph of this standard, is established in regulatory documentation and there should be no more than 5. The influence function is not normalized if the additional error within the conditions specified in clause of this standard does not exceed 20% of the limit of the permissible main error. 2.6. The nominal value of the concentration of a harmful substance that causes the appearance of an indication effect in colorimetric indicator tubes (response concentration) is expressed in mg/m 3 . 2.7. The error of the colorimetric indicator tube is characterized by the limit of the permissible relative error of the response concentration. The values of the maximum permissible main error must be selected from the range established in GOST 8.401-80. 2.8. The regulatory documentation for specific indicator tubes includes data on impurities in the gas-air environment that interfere with the measurement of concentrations of a given harmful substance. An impurity is considered non-interfering if, when the impurity concentration is at a level of 5 maximum permissible values for it, the value of the main error of the indicator tube is less than the established limit. 2.9. The regulatory documentation for indicator tubes must indicate storage conditions and guarantee period storage, during which the error values of the indicator tubes are within the established limits. The warranty period values for the storage of indicator tubes are selected from row 1; 1.5; 2; 3 and 5 years old. 2.10. The volume of air sucked through the indicator tube using an air intake device is expressed in cm 3. The dosing error of the volume of sucked air is characterized by the limit of the permissible value and is selected from the range of 5, 3, 2, 1 and 0.5%. Air intake device designed for use with indicator tube, must have the same flow characteristics as the air intake device used to calibrate the indicator tube. |
GOST 12.1.014-84
Group T58
INTERSTATE STANDARD
Occupational Safety Standards System
WORKING AREA AIR
Method for measuring concentrations of harmful substances using indicator tubes
Occupational safety standards system. Air in the zone of operation. Method of measuring unhealthy matters concentration using indicator tubes
ISS 13.040.30
OKSTU 0012
Date of introduction 1986-01-01
By Decree of the USSR State Committee on Standards dated December 14, 1984 N 4362, the implementation date was set as 01/01/86
The validity period was lifted according to Protocol No. 5-94 of the Interstate Council for Standardization, Metrology and Certification (IUS 11-12-94)
INSTEAD GOST 12.1.014-79
EDITION (October 2010) with Change No. 1, approved in March 1990 (IUS 7-90).
This standard establishes an accelerated method for measuring concentrations of harmful substances in the air of a working area using indicator tubes, except for the air of underground mines.
The essence of the method is to change the color of the indicator powder as a result of a reaction with a harmful substance (gas or steam) in the analyzed air sucked through the tube. The concentration of a harmful substance is measured by the length of the layer of indicator powder in the tube that has changed its original color (linear-color indicator tube) or by its intensity (colorimetric indicator tube).
The terms used in the standard and their explanations are given in Appendix 1.
The characteristics of the produced indicator powders are given in Appendix 2.
The standardized metrological characteristics of indicator tubes and air intake devices for them are given in Appendix 3.
1. EQUIPMENT
1. EQUIPMENT
1.1. Indicator tubes, including those equipped by the consumer using special kits with indicator powders.
1.2. Filter tubes, including those equipped by the consumer using special kits.
1.3. An air intake device (such as a pump, bellows, etc.) designed for use with this indicator tube.
2. PREPARATION FOR MEASUREMENT
2.1. Preparation of equipment for measuring concentrations of harmful substances in the air of the working area is carried out in accordance with the regulatory and technical documentation for indicator and filter tubes and the air intake device intended for them.
2.2. In unstudied production conditions, before carrying out measurements with indicator tubes, it is necessary to conduct a one-time qualitative assessment of the air composition of the working area using certified methods or guidelines approved by the USSR Ministry of Health. Based on the data obtained, the possibility of using indicator tubes for planned or operational monitoring is established. Regardless of the composition of the air in the working area, the use of filter tubes with indicator tubes, if provided for in the regulatory and technical documentation for indicator tubes, is mandatory in order to avoid violation of the operating conditions of the indicator tubes.
A repeated qualitative assessment of the air composition of the working area should be carried out with each change in production technology, which may cause the appearance of new harmful substances in the air environment.
2.1, 2.2. (Changed edition, Amendment No. 1).
3. MEASUREMENT
3.1. Measurement of concentrations of harmful substances in the air of the working area is carried out under the following parameters:
barometric pressure - from 90 to 104 kPa (680-780 mm Hg);
relative humidity - 30-80%;
temperature - from 288 to 303 K.
Deviations from the specified parameters are allowed if this is provided for in the regulatory and technical documentation for measuring instruments.
Control metrological parameters air of the working area should be carried out in parallel with measurements of concentrations of harmful substances with indicator tubes.
3.2. An indicator tube designed to measure the concentration of a harmful substance, and filter tubes, if they are provided for in the regulatory and technical documentation, are connected to the air intake device.
Measurement should begin no later than 1 minute after depressurization of the tubes.
3.1, 3.2. (Changed edition, Amendment No. 1).
3.3. The amount of air sucked through the indicator tubes is set in accordance with the regulatory and technical documentation for these tubes.
3.4. Measurement of concentrations of harmful substances is carried out sequentially under production conditions in accordance with GOST 12.1.005-88. In this case, the number of indicator tubes specified in the relevant regulatory and technical documentation is used.
3.5. The concentration of a harmful substance in mg/m in the air of the working area is measured by the length or intensity of the layer of indicator powder that has changed its original color using a scale applied to the indicator tube, cassette or special label. The arithmetic mean of successive observations is taken as the measurement result, as indicated in clause 3.4.
3.6. If the boundary between the colors of the layers of the original and reacted indicator powder is blurred, the concentration of the measured harmful substance is measured on a scale along the lower and upper parts of the boundary. The average value is taken as the measurement result.
3.7. The result of measuring the concentration of a harmful substance leads to normal conditions (): temperature 293 K, atmospheric pressure 101.3 kPa (760 mm Hg), relative humidity 60%.
Concentration () under normal conditions in mg/m is calculated using the formula
where is the result of measuring the concentration of a harmful substance at ambient temperature °C, relative humidity % and atmospheric pressure kPa, mg/m;
- coefficient taking into account the influence of ambient temperature and humidity on the readings of indicator tubes, the value of which is determined in accordance with clause 2.5 of Appendix 3.
The relative measurement error should not exceed ±35% in the range up to 2.0 maximum permissible concentrations (MPC), inclusive, and ±25% at concentrations above 2.0 MAC under the conditions specified in clause 3.1.
The measurement result is presented as: mg/m with a confidence probability of 0.95.
Size absolute error calculated by the formula
In the range up to 1.0 MPC inclusive, an increase in error of up to ±60% is allowed. This relative error value must be indicated in the regulatory and technical documentation for the measuring instruments.
(Changed edition, Amendment No. 1).
4. SAFETY REQUIREMENTS
4.1. When measuring the concentrations of harmful substances with indicator tubes in the air of the working area, you must comply with the safety standards and regulations in force in this production.
4.2. Measurement of concentrations of harmful substances with indicator tubes is carried out by persons who have been trained and authorized to work on monitoring harmful substances in the air of the working area.
4.3. When opening the tubes, it is necessary to take all precautions when working with glass, using special devices and protective equipment.
APPENDIX 1 (for reference). TERMS USED IN THE STANDARD AND THEIR EXPLANATIONS
ANNEX 1
Information
Explanation |
|
Work zone | |
Method for measuring the concentration of harmful substances | At the stages of development of indicator tubes, their main error is characterized by: the limit of the permissible value of the systematic component of the main error, the limit of the permissible value of the standard deviation of the random component of the main error. 2.4. The number of sequentially used indicator tubes, ensuring a reduction in the error of the measurement result of the concentration of a harmful substance to values not exceeding those established in clause 3.7 of this standard, is established in the regulatory and technical documentation and should be no more than 5. 2.5. The influence function is normalized in the form of a graph or table and takes into account the influence on the readings of the indicator tube of joint changes in temperature and relative humidity of the ambient air within the conditions specified in clause 3.1 of this standard. The influence function is not standardized if the additional error within the conditions specified in clause 3.1 of this standard does not exceed 20% of the limit of the permissible main error. 2.6. The nominal value of the concentration of a harmful substance that causes the appearance of an indication effect in colorimetric indicator tubes (response concentration) is expressed in mg/m. 2.7. The error of the colorimetric indicator tube is characterized by the limit of the permissible relative error of the response concentration. The values of the maximum permissible basic error must be selected from the range established in GOST 8.401-80. 2.8. The regulatory and technical documentation for specific indicator tubes includes data on impurities in the gas-air environment that interfere with the measurement of concentrations of a given harmful substance. An impurity is considered non-interfering if, with an impurity concentration at a level of 5 maximum permissible values for it, the value of the main error of the indicator tube is less than the established limit. 2.9. The regulatory and technical documentation for indicator tubes must indicate storage conditions and a guaranteed storage period during which the error values of the indicator tubes are within the established limits. The values of the guaranteed shelf life of indicator tubes are selected from row 1; 1.5; 2; 3 and 5 years old. 2.10. The volume of air drawn through the indicator tube by the air intake device is expressed in cm. The dosing error of the volume of sucked air is characterized by the limit of the permissible value and is selected from the range of 5, 3, 2, 1 and 0.5%. The air intake device intended for use with the indicator tube must have the same flow characteristics as the air intake device used for calibration of the indicator tube. Electronic document text |
STATE STANDARD OF THE USSR UNION
Occupational Safety Standards System
Work area air
Method for measuring concentrations of harmful substances
indicator tubes
GOST 12.1.014-84
MOSCOW
APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated December 14, 1984 No. 4362
INSTEAD GOST 12.1.014-79
The validity period was lifted by decision of the Interstate Council for Standardization, Metrology and Certification (Protocol No. 5-94)
REISSUE (January 1996) with Change No. 1, approved in March 1990 (IUS 7-90)
This standard establishes an accelerated method for measuring concentrations of harmful substances in the air of a working area using indicator tubes, except for the air of underground mines.
The essence of the method is to change the color of the indicator powder as a result of a reaction with a harmful substance (gas or steam) in the analyzed air sucked through the tube. The concentration of a harmful substance is measured by the length of the layer of indicator powder in the tube that has changed its original color (linear-color indicator tube) or by its intensity (colorimetric indicator tube).
The terms used in the standard and their explanations are given in the Appendix.
The characteristics of the produced indicator powders are given in the Appendix.
The standardized metrological characteristics of indicator tubes and air intake devices for them are given in the Appendix.
STATE STANDARD OF THE USSR UNION
|
Occupational Safety Standards System Work area air Method for measuring concentrations of harmful substances indicatortubes Occupational safety standards system. |
GOST In return |
Date of introduction 1986-01-01
1. EQUIPMENT
1.1. Indicator tubes, including those equipped by the consumer using special kits with indicator powders.
1.2. Filter tubes, including those equipped by the consumer using special kits.
1.3. An air intake device (such as a pump, bellows, etc.) designed for use with this indicator tube.
2. PREPARATION FOR MEASUREMENT
2.1. Preparation of equipment for measuring concentrations of harmful substances in the air of the working area is carried out in accordance with the regulatory documentation for indicator and filter tubes and the air intake device intended for them.
2.2. In unstudied production conditions, before carrying out measurements with indicator tubes, it is necessary to conduct a one-time qualitative assessment of the air composition of the working area using certified methods or guidelines approved by the USSR Ministry of Health. Based on the data obtained, the possibility of using indicator tubes for planned or operational monitoring is established. Regardless of the composition of the air in the working area, the use of filter tubes with indicator tubes, if provided for in the regulatory documentation for indicator tubes, is mandatory in order to avoid violating the operating conditions of the indicator tubes.
A repeated qualitative assessment of the air composition of the working area should be carried out with each change in production technology, which may cause the appearance of new harmful substances in the air environment.
2.1, 2.2 (Changed edition, Amendment No. 1).
3. MEASUREMENT
barometric pressure - from 90 to 104 kPa (680-780 mm Hg);
relative humidity - 30 - 80%;
temperature - from 288 to 303 K.
Deviations from the specified parameters are allowed if this is provided for in the regulatory and technical documentation for measuring instruments.
Monitoring the metrological parameters of the air in the working area should be carried out in parallel with measuring the concentrations of harmful substances using indicator tubes.
3.2. An indicator tube designed to measure the concentration of a harmful substance and filter tubes, if provided for by regulatory documentation, are connected to the air intake device.
Measurement should begin no later than 1 minute after depressurization of the tubes.
3.1, 3.2 (Changed edition, Amendment No. 1).
3.3. The amount of air sucked through the indicator tubes is set in accordance with the regulatory documentation for these tubes.
3.6. If the boundary between the colors of the layers of the original and reacted indicator powder is blurred, the concentration of the measured harmful substance is measured on a scale along the lower and upper parts of the boundary. The average value is taken as the measurement result.
Concentration ( WITH m) under normal conditions in mg/m3 is calculated using the formula
where is the result of measuring the concentration of a harmful substance at ambient temperature, t°C, relative humidity φ% and atmospheric pressure R kPa, mg/m3;
K B is a coefficient that takes into account the influence of temperature and humidity of the ambient air on the readings of indicator tubes, the value of which is determined in accordance with paragraph of the appendix.
The relative measurement error (δ) should not exceed ±35% in the range up to 2.0 maximum permissible concentrations (MPC), inclusive, and ±25% at concentrations above 2.0 MAC under the conditions specified in clause .
The measurement result is presented as: ( WITH H ± Δ) mg/m3 at a confidence level of 0.95.
The absolute error D is calculated using the formula
In the range up to 1.0 MPC inclusive, an increase in error of up to ±60% is allowed. This relative error value must be indicated in the regulatory and technical documentation for the measuring instruments.
(Changed edition, Amendment No. 1).
4. SAFETY REQUIREMENTS
4.1. When measuring the concentrations of harmful substances with indicator tubes in the air of the working area, you must comply with the safety standards and regulations in force in this production.
4.2. Measurement of concentrations of harmful substances with indicator tubes is carried out by persons who have been trained and authorized to work on monitoring harmful substances in the air of the working area.
4.3. When opening the tubes, it is necessary to take all precautions when working with glass, using special devices and protective equipment.
APPLICATION 1
Information
TERMS USED IN THE STANDARD AND THEIR EXPLANATIONS
|
Explanation |
|
|
Work zone |
|
|
Method for measuring the concentration of harmful substances |
According to GOST 16263-70 |
|
Harmful substance |
|
|
Maximum permissible concentrations of harmful substances in the air of the working area |
|
|
Indicator tube |
Primary measuring transducer, structurally consisting of a glass tube filled with granular filler (indicator powder) |
|
Linear color indicator tube |
An indicator tube that allows you to measure the concentration of a harmful substance in the analyzed air sucked through the tube along the length of the layer of indicator powder in the tube that has changed its original color |
|
Colorimetric indicator tube |
An indicator tube that makes it possible to judge the presence of a harmful substance in the analyzed air sucked through the tube, in a concentration greater than the response concentration for a given indicator tube, by the color intensity of the indicator powder by comparison with a control sample of the indicator effect |
|
Filter tube |
A glass tube filled with one or more absorbers that serve to trap gases and vapors that interfere with the measurement of a harmful substance |
|
Indicator powder |
A granular chemisorbent that changes color when a directly detectable harmful substance or its volatile products of interaction with the chemisorbent in the filter tube passes through it |
|
Absorber |
A granular sorbent or chemisorbent that completely transmits the harmful substance being determined and traps accompanying substances that interfere with the analysis |
|
Reading range |
The range of values of the indicator tube scale, limited by the final and initial values of the scale |
|
Lower (upper) limit |
The smallest (highest) value of the measured concentrations |
|
Air intake device |
Device for sucking air through indicator tubes |
(Changed edition, Amendment No. 1).
APPLICATION 2
Information
CHARACTERISTICS OF PRODUCED INDICATOR POWDERS FOR EQUIPING INDICATOR TUBES
|
Determined gas (steam) |
Air volume sucked in, cm3 |
Measuring range, mg/m3 |
Total air suction time, s |
Gas (steam) captured by the filter cartridge |
Gas (steam) interfering with determination |
|
Nitrogen oxides |
Halogens (chlorine, bromine, iodine), ozone in concentrations above 10 MAC |
||||
|
Vapors of acids, alkalis and amines |
|||||
|
Sulfur dioxide |
Hydrogen sulfide, ammonia, nitrogen dioxide, sulfuric acid mist, water vapor |
||||
|
Acetylene |
Hydrogen sulfide, hydrogen phosphide, silicon hydrogen, ammonia, acetone and water vapor |
||||
|
Sulfur dioxide, vapors of acetic acid, acetic anhydride, hydrochloric acid, in concentrations up to 10 MPC |
Vapors of ketones and esters, vapors of acetic acid, acetic anhydride, hydrochloric acid and sulfuric anhydride in concentrations above 10 MAC |
||||
|
Aromatic and unsaturated hydrocarbons, water vapor |
|||||
|
Water vapor |
|||||
|
Water vapor |
Fatty and aromatic hydrocarbon vapors |
||||
|
Hydrogen sulfide |
Mercaptans |
||||
|
Water vapor |
Fatty and aromatic hydrocarbon vapors |
||||
|
Petroleum hydrocarbons |
Unsaturated and aromatic hydrocarbons, water vapor |
||||
|
Carbon oxide |
Acetylene, ethylene, methane, a mixture of butane and propane, nitrogen oxides, chlorine, sulfur dioxide, hydrogen, gasoline vapors, benzene and its homologues, water, acetone, formic acid, formaldehyde, ethyl and methyl alcohols, dichloroethane, carbon disulfide |
Metal carbonyl vapors |
|||
|
Vapors of bromine, iodine, oxidizing agents, chloramines |
|||||
|
Ethyl ether |
Water vapor, ethyl alcohol, organic acids, phenol |
(Changed edition, Amendment No. 1).
APPLICATION 3
Information
NORMALIZED METROLOGICAL CHARACTERISTICS OF INDICATOR TUBES AND AIR INCLUSION DEVICES FOR THEM
1. Metrological characteristics
1.1. For linear-color indicator tubes, the following metrological characteristics are established:
nominal static conversion characteristic,
range of measured concentrations,
main error
relative error,
influence functions caused by a change in an influencing quantity within operating conditions.
1.2. The characteristics of indicator tubes designed to determine the presence of a harmful substance in the air of the working area (colorimetric indicator tubes) are:
nominal value of the concentration of a harmful substance causing the appearance of an indication effect (activation concentration);
operation error.
1.3. The following metrological characteristics are established for air intake devices:
volume of sucked air,
error in dosing the volume of sucked air.
Instead of volume, it is permissible to normalize the duration of suction and the volumetric flow rate of air sucked through the indicator tube.
2. Methods of standardization and forms of presentation of metrological characteristics
2.1. The nominal static conversion characteristic is presented in the form of a formula or graph, which corresponds to a scale printed on an indicator tube, cassette or special label.
2.2. The range of measured concentrations is characterized by its lower and upper boundaries. The lower limit of the measurement range should be no more than 0.5 maximum permissible concentration, and the upper limit - no less than 5 maximum permissible concentrations for a given substance.
It is possible to divide the measurement range into several subranges by changing the volume of air sucked through the indicator tube, setting a nominal static conversion characteristic for each of these volumes.
If the reading range does not coincide with the measurement range, then the reading range is normalized by setting the initial and final scale values.
2.3. The main error of indicator tubes is characterized by the limit of permissible main error. The values of the maximum permissible basic error must be selected from the range established in GOST 8.401-80.
At the stages of development of indicator tubes, their main error is characterized by:
the limit of the permissible value of the systematic component of the main error,
the limit of the permissible value of the standard deviation of the random component of the main error.
2.4. The number of sequentially used indicator tubes, ensuring a reduction in the error in the measurement result of the concentration of a harmful substance to values not exceeding those established in paragraph of this standard, is established in the regulatory documentation and should be no more than 5.
2.8. The regulatory documentation for specific indicator tubes includes data on impurities in the gas-air environment that interfere with the measurement of concentrations of a given harmful substance. An impurity is considered non-interfering if, with an impurity concentration at a level of 5 maximum permissible values for it, the value of the main error of the indicator tube is less than the established limit.
2.9. The regulatory documentation for indicator tubes must indicate the storage conditions and the guaranteed storage period during which the error values of the indicator tubes are within the established limits.
The values of the guaranteed shelf life of indicator tubes are selected from row 1; 1.5; 2; 3 and 5 years old.
2.10. The volume of air drawn through the indicator tube using an air intake device is expressed in cm3.
The dosing error of the volume of sucked air is characterized by the limit of the permissible value and is selected from the range of 5, 3, 2, 1 and 0.5%.
The air intake device intended for use with the indicator tube must have the same flow characteristics as the air intake device used for calibration of the indicator tube.
Interstate standard GOST 12.1.014-84
"System of occupational safety standards. Work area air. Method for measuring concentrations of harmful substances with indicator tubes"
(approved by Decree of the USSR State Standard of December 14, 1984 N 4362)
Occupational safety standards system. Air in the zone of operation. Method of measuring unhealthy matters concentration using indicator tubes.
Instead of GOST 12.1.014-79
This standard establishes an accelerated method for measuring concentrations of harmful substances in the air of a working area using indicator tubes, except for the air of underground mines.
The essence of the method is to change the color of the indicator powder as a result of a reaction with a harmful substance (gas or steam) in the analyzed air sucked through the tube. The concentration of a harmful substance is measured by the length of the layer of indicator powder in the tube that has changed its original color (linear-color indicator tube) or by its intensity (colorimetric indicator tube).
The terms used in the standard and their explanations are given in Appendix 1.
The characteristics of the produced indicator powders are given in Appendix 2.
Standardized metrological characteristics of indicator tubes and air intake devices for them are given in Appendix 3.
1. Equipment
1.1. Indicator tubes, including those equipped by the consumer using special kits with indicator powders.
1.2. Filter tubes, including those equipped by the consumer using special kits.
1.3. An air intake device (such as a pump, bellows, etc.) designed for use with this indicator tube.
2. Preparation for measurement
2.1. Preparation of equipment for measuring concentrations of harmful substances in the air of the working area is carried out in accordance with the regulatory and technical documentation for indicator and filter tubes and the air intake device intended for them.
2.2. In unstudied production conditions, before carrying out measurements with indicator tubes, it is necessary to conduct a one-time qualitative assessment of the air composition of the working area using certified methods or guidelines approved by the USSR Ministry of Health. Based on the data obtained, the possibility of using indicator tubes for planned or operational monitoring is established. Regardless of the composition of the air in the working area, the use of filter tubes with indicator tubes, if provided for in the regulatory and technical documentation for indicator tubes, is mandatory in order to avoid violation of the operating conditions of the indicator tubes.
A repeated qualitative assessment of the air composition of the working area should be carried out with each change in production technology, which may cause the appearance of new harmful substances in the air environment.
2.1, 2.2. (Changed edition, Amendment No. 1).
3. Taking measurements
3.1. Measurement of concentrations of harmful substances in the air of the working area is carried out under the following parameters:
barometric pressure - from 90 to 104 kPa (680-780 mm Hg);
relative humidity - 30-80%;
temperature - from 288 to 303 K.
Deviations from the specified parameters are allowed if this is provided for in the regulatory and technical documentation for measuring instruments.
Monitoring the meteorological parameters of the air in the working area should be carried out in parallel with measuring the concentrations of harmful substances using indicator tubes.
3.2. An indicator tube designed to measure the concentration of a harmful substance, and filter tubes, if they are provided for in the regulatory and technical documentation, are connected to the air intake device.
Measurement should begin no later than 1 minute after depressurization of the tubes.
3.1, 3.2. (Changed edition, Amendment No. 1).
3.3. The amount of air sucked through the indicator tubes is set in accordance with the regulatory and technical documentation for these tubes.
3.4. Measurement of concentrations of harmful substances is carried out sequentially under production conditions in accordance with GOST 12.1.005-88. In this case, the number of indicator tubes specified in the relevant regulatory and technical documentation is used.
3.5. The concentration of a harmful substance in mg/m3 in the air of the working area is measured by the length or intensity of the layer of indicator powder that has changed its original color using a scale applied to the indicator tube, cassette or special label. The arithmetic mean of successive observations is taken as the measurement result, as indicated in clause 3.4.
3.6. If the boundary between the colors of the layers of the original and reacted indicator powder is blurred, the concentration of the measured harmful substance is measured on a scale along the lower and upper parts of the boundary. The average value is taken as the measurement result.
3.7. The result of measuring the concentration of a harmful substance leads to normal conditions (С_н): temperature 293 K, atmospheric pressure 101.3 kPa (760 mm Hg), relative humidity 60%.
Concentration (С_н) under normal conditions in mg/m3 is calculated using the formula
_ (273 + t) x 101.3 C = C, phi, p ------------------ x K, n t 293 x p in _ where C, phi, p is the result of measuring the concentration of a harmful substance, t at ambient temperature t°C, relative humidity fi % and atmospheric pressure p kPa, mg/m3; K is a coefficient that takes into account the influence of temperature and humidity of the ambient air on the readings of indicator tubes, the value of which is determined in accordance with paragraph 2.5 of Appendix 3.
The relative measurement error (delta) should not exceed + -35% in the range up to 2.0 maximum permissible concentrations (MPC) inclusive and + -25% at concentrations above 2.0 MAC under the conditions specified in clause 3.1.
The measurement result is presented in the form: (C_n+-Delta) mg/m3 with a confidence probability of 0.95. The absolute error (Delta) is calculated using the formula
Delta Delta = C ------. n 100
In the range up to 1.0 MPC inclusive, an increase in error up to +-60% is allowed. This relative error value must be indicated in the regulatory and technical documentation for the measuring instruments.
(Changed edition, Amendment No. 1).
4. Safety requirements
4.1. When measuring the concentrations of harmful substances with indicator tubes in the air of the working area, you must comply with the safety standards and regulations in force in this production.
4.2. Measurement of concentrations of harmful substances with indicator tubes is carried out by persons who have been trained and authorized to work on monitoring harmful substances in the air of the working area.
4.3. When opening the tubes, it is necessary to take all precautions when working with glass, using special devices and protective equipment.
Open the current version of the document right now or get full access to the GARANT system for 3 days for free!
If you are a user of the Internet version of the GARANT system, you can open this document right now or request by Hotline in system.
Work area air
Method for measuring concentrations of harmful substances
indicator tubes
GOST 12.1.014-84
STATE STANDARD OF THE USSR UNION
Occupational Safety Standards System
Work area air
Method for measuring concentrations of harmful substances GOST
indicator tubes 12.1.014-84
Occupational safety standards system. Air of In return
the work zone. Method of measuring GOST 12.1.014-79
unhealthy matters concentration using
Date of introduction 1986-01-01
APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated December 14, 1984 No. 4362
INSTEAD GOST 12.1.014-79
The validity period was lifted by decision of the Interstate Council for Standardization, Metrology and Certification (Protocol No. 5-94)
REISSUE (January 1996) with Change No. 1, approved in March 1990 (IUS 7-90)
This standard establishes an accelerated method for measuring concentrations of harmful substances in the air of a working area using indicator tubes, except for the air of underground mines.
The essence of the method is to change the color of the indicator powder as a result of a reaction with a harmful substance (gas or steam) in the analyzed air sucked through the tube. The concentration of a harmful substance is measured by the length of the layer of indicator powder in the tube that has changed its original color (linear-color indicator tube) or by its intensity (colorimetric indicator tube).
The terms used in the standard and their explanations are given in Appendix 1.
The characteristics of the produced indicator powders are given in Appendix 2.
The standardized metrological characteristics of indicator tubes and air intake devices for them are given in Appendix 3.
1. Equipment
1.1. Indicator tubes, including those equipped by the consumer using special kits with indicator powders.
1.2. Filter tubes, including those equipped by the consumer using special kits.
1.3. An air intake device (such as a pump, bellows, etc.) designed for use with this indicator tube.
2. Preparation for measurement
2.1. Preparation of equipment for measuring concentrations of harmful substances in the air of the working area is carried out in accordance with the regulatory documentation for indicator and filter tubes and the air intake device intended for them.
2.2. In unstudied production conditions, before carrying out measurements with indicator tubes, it is necessary to conduct a one-time qualitative assessment of the air composition of the working area using certified methods or guidelines approved by the USSR Ministry of Health. Based on the data obtained, the possibility of using indicator tubes for planned or operational monitoring is established. Regardless of the composition of the air in the working area, the use of filter tubes with indicator tubes, if provided for in the regulatory documentation for indicator tubes, is mandatory in order to avoid violating the operating conditions of the indicator tubes.
A repeated qualitative assessment of the air composition of the working area should be carried out with each change in production technology, which may cause the appearance of new harmful substances in the air environment.
2.1, 2.2 (Changed edition, Amendment No. 1).
3. Taking measurements
3.1. Measurement of concentrations of harmful substances in the air of the working area is carried out under the following parameters:
barometric pressure - from 90 to 104 kPa (680-780 mm Hg);
relative humidity - 30-80%;
temperature - from 288 to 303 K.
Deviations from the specified parameters are allowed if this is provided for in the regulatory and technical documentation for measuring instruments.
Monitoring the metrological parameters of the air in the working area should be carried out in parallel with measuring the concentrations of harmful substances using indicator tubes.
3.2. An indicator tube designed to measure the concentration of a harmful substance and filter tubes, if provided for by regulatory documentation, are connected to the air intake device.
Measurement should begin no later than 1 minute after depressurization of the tubes.
3.1, 3.2 (Changed edition, Amendment No. 1).
3.3. The amount of air sucked through the indicator tubes is set in accordance with the regulatory documentation for these tubes.
3.4. Measurement of concentrations of harmful substances is carried out sequentially under production conditions in accordance with GOST 12.1.005-88. In this case, the number of indicator tubes specified in the relevant regulatory documentation is used.
3.5. The concentration of a harmful substance in mg/m 3 in the air of the working area is measured by the length or intensity of the layer of indicator powder that has changed its original color using a scale applied to the indicator tube, cassette or special label. The arithmetic mean of successive observations is taken as the measurement result, as specified in 3.4.
3.6. If the boundary between the colors of the layers of the original and reacted indicator powder is blurred, the concentration of the measured harmful substance is measured on a scale along the lower and upper parts of the boundary. The average value is taken as the measurement result.
3.7 The result of measuring the concentration of a harmful substance leads to normal conditions ( S n): temperature 293 K, atmospheric pressure 101.3 kPa (760 mm Hg), relative humidity 60%.
Concentration ( S n) under normal conditions in mg/m3 is calculated using the formula
where is the result of measuring the concentration of a harmful substance at ambient temperature, t°C, relative humidity
- % and atmospheric pressure kPa, mg/m 3 ;
A coefficient that takes into account the influence of ambient temperature and humidity on the readings of indicator tubes, the value of which is determined in accordance with clause 2.5 of Appendix 3.
The relative measurement error should not exceed ± 35% in the range up to 2.0 maximum permissible concentrations (MPC), inclusive, and ± 25% at concentrations above 2.0 MAC under the conditions specified in clause 3.1.
The measurement result is presented as: mg/m 3 with a confidence probability of 0.95.
The magnitude of the absolute error D calculated by the formula
In the range up to 1.0 MPC inclusive, an increase in error of up to ± 60% is allowed. This relative error value must be indicated in the regulatory and technical documentation for the measuring instruments.
(Changed edition, Amendment No. 1).
4. Safety requirements
4.1. When measuring the concentrations of harmful substances with indicator tubes in the air of the working area, you must comply with the safety standards and regulations in force in this production.
4.2. Measurement of concentrations of harmful substances with indicator tubes is carried out by persons who have been trained and authorized to work on monitoring harmful substances in the air of the working area.
4.3. When opening the tubes, it is necessary to take all precautions when working with glass, using special devices and protective equipment.
Annex 1
(informative)
Terms used in the standard and their explanations
|
Term |
Explanation |
|
Work zone |
According to GOST 12.1.005-88 |
|
Method for measuring the concentration of harmful substances |
According to GOST 16263-70 |
|
Harmful substance |
According to GOST 12.1.007-76 |
|
Maximum permissible concentrations of harmful substances in the air of the working area |
According to GOST 12.1.005-88 |
|
Indicator tube |
Primary measuring transducer, structurally consisting of a glass tube filled with granular filler (indicator powder) |
|
Linear color indicator tube |
An indicator tube that allows you to measure the concentration of a harmful substance in the analyzed air sucked through the tube along the length of the layer of indicator powder in the tube that has changed its original color |
|
Colorimetric indicator tube |
An indicator tube that makes it possible to judge the presence of a harmful substance in the analyzed air sucked through the tube, in a concentration greater than the response concentration for a given indicator tube, by the color intensity of the indicator powder by comparison with a control sample of the indicator effect |
|
Filter tube |
A glass tube filled with one or more absorbers that serve to trap gases and vapors that interfere with the measurement of a harmful substance |
|
Indicator powder |
A granular chemisorbent that changes color when a directly detectable harmful substance or its volatile products of interaction with the chemisorbent in the filter tube passes through it |
|
Absorber |
A granular sorbent or chemisorbent that completely transmits the harmful substance being determined and traps accompanying substances that interfere with the analysis |
|
Reading range |
The range of values of the indicator tube scale, limited by the final and initial values of the scale |
|
Lower (upper) limit |
The smallest (highest) value of the measured concentrations |
|
Air intake device |
Device for sucking air through indicator tubes |
(Changed edition, Amendment No. 1)
Appendix 2
(informative)
Characteristics of produced indicator powders for equipping indicator tubes
|
Determined gas (steam) |
Air volume sucked in, cm 3 |
Measuring range, mg/m 3 |
Total air suction time, s |
Gas (steam) captured by the filter cartridge |
Gas (steam) interfering with determination |
|
Nitrogen oxides |
2,5-50 |
Halogens (chlorine, bromine, iodine), ozone in concentrations above 10 MAC |
|||
|
Ammonia |
2,5-30 |
Acid fumes |
|||
|
20-100 |
alkalis and amines |
||||
|
Anhydride |
5-30 |
Hydrogen sulfide, |
|||
|
sulfur |
20-120 |
ammonia, nitrogen dioxide, sulfuric acid mist, water vapor |
|||
|
Acetylene |
50-1400 |
Hydrogen sulfide, phosphorous |
|||
|
1000-3000 |
hydrogen, silicon hydrogen, ammonia, acetone and water vapor |
||||
|
Acetone |
100-2000 |
Sulfur dioxide, vapors of acetic acid, acetic anhydride, hydrochloric acid, in concentrations up to 10 MPC |
Vapors of ketones and esters, vapors of acetic acid, acetic anhydride, hydrochloric acid and sulfuric anhydride in concentrations above 10 MAC |
||
|
Petrol |
50-1000 |
Aromatic and unsaturated hydrocarbons, water vapor |
|||
|
Benzene |
400 ´ 3 |
2-25 |
360 ´ 3 |
Water vapor |
|
|
Xylene |
25-500 |
Water vapor |
Fatty and aromatic hydrocarbon vapors |
||
|
Hydrogen sulfide |
5-30 |
Mercaptans |
|||
|
Toluene |
25-500 |
Water vapor |
Fatty and aromatic hydrocarbon vapors |
||
|
Petroleum hydrocarbons |
100-1500 |
Unsaturated and aromatic hydrocarbons, water vapor |
|||
|
Carbon oxide |
5-120 |
Acetylene, ethylene, methane, a mixture of butane and propane, nitrogen oxides, chlorine, sulfur dioxide, hydrogen, gasoline vapors, benzene and its homologues, water, acetone, formic acid, formaldehyde, ethyl and methyl alcohols, dichloroethane, carbon disulfide |
Metal carbonyl vapors |
||
|
Chlorine |
0,15-15 |
Vapors of bromine, iodine, oxidizing agents, chloramines |
|||
|
Ethyl ether |
100-3000 |
Vapors of water, ethyl alcohol, organic acids, phenol |
(Changed edition, Amendment No. 1).
Appendix 3
(informative)
Standardized metrological characteristics of indicator tubes and air intake devices for them
1. Metrological characteristics
1.1. For linear-color indicator tubes, the following metrological characteristics are established:
nominal static conversion characteristic,
range of measured concentrations,
main error
relative error,
influence functions caused by a change in an influencing quantity within operating conditions.
1.2. The characteristics of indicator tubes designed to determine the presence of a harmful substance in the air of the working area (colorimetric indicator tubes) are:
nominal value of the concentration of a harmful substance causing the appearance of an indication effect (activation concentration);
operation error.
1.3. The following metrological characteristics are established for air intake devices:
volume of sucked air,
error in dosing the volume of sucked air.
Instead of volume, it is permissible to normalize the duration of suction and the volumetric flow rate of air sucked through the indicator tube.
2. Methods of standardization and forms of presentation of metrological characteristics
2.1. The nominal static conversion characteristic is presented in the form of a formula or graph, which corresponds to a scale printed on an indicator tube, cassette or special label.
2.2. The range of measured concentrations is characterized by its lower and upper boundaries. The lower limit of the measurement range should be no more than 0.5 maximum permissible concentration, and the upper limit - no less than 5 maximum permissible concentrations for a given substance.
It is possible to divide the measurement range into several subranges by changing the volume of air sucked through the indicator tube, setting a nominal static conversion characteristic for each of these volumes.
If the reading range does not coincide with the measurement range, then the reading range is normalized by setting the initial and final scale values.
2.3. The main error of indicator tubes is characterized by the limit of permissible main error. The values of the maximum permissible basic error must be selected from the range established in GOST 8.401-80.
At the stages of development of indicator tubes, their main error is characterized by:
the limit of the permissible value of the systematic component of the main error,
the limit of the permissible value of the standard deviation of the random component of the main error.
2.4. The number of sequentially used indicator tubes, ensuring a reduction in the error of the measurement result of the concentration of a harmful substance to values not exceeding those established in clause 3.7 of this standard, is established in the regulatory documentation and should be no more than 5.
2.5. The influence function is normalized in the form of a graph or table and takes into account the influence on the readings of the indicator tube of joint changes in temperature and relative humidity of the ambient air within the conditions specified in 3.1 of this standard.
The influence function is not standardized if the additional error within the conditions specified in 3.1 of this standard does not exceed 20% of the limit of the permissible main error.
2.6. The nominal value of the concentration of a harmful substance that causes the appearance of an indication effect in colorimetric indicator tubes (response concentration) is expressed in mg/m 3 .
2.7. The error of the colorimetric indicator tube is characterized by the limit of the permissible relative error of the response concentration. The values of the maximum permissible basic error must be selected from the range established in GOST 8.401-80.
2.8. The regulatory documentation for specific indicator tubes includes data on impurities in the gas-air environment that interfere with the measurement of concentrations of a given harmful substance. An impurity is considered non-interfering if, with an impurity concentration at a level of 5 maximum permissible values for it, the value of the main error of the indicator tube is less than the established limit.
2.9. The regulatory documentation for indicator tubes must indicate the storage conditions and the guaranteed storage period during which the error values of the indicator tubes are within the established limits.
The values of the guaranteed shelf life of indicator tubes are selected from row 1; 1.5; 2; 3 and 5 years old.
2.10. The volume of air sucked through the indicator tube using an air intake device is expressed in cm 3.
The dosing error of the volume of sucked air is characterized by the limit of the permissible value and is selected from the range of 5, 3, 2, 1 and 0.5%.
The air intake device intended for use with the indicator tube must have the same flow characteristics as the air intake device used for calibration of the indicator tube.