GB/T 18204.1-2025 Examination methods for public places – Part 1: Physical indicators
1 Scope
This document describes the methods for measuring physical indicators in public places.
This document is applicable to the measurement of physical indicators in public places. Other places, such as residential rooms and other indoor environments, should refer to this document for guidance.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 18049 Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria
GB/T 18883 Standards for indoor air quality
HJ/T 10.2 Guideline on management of radioactive environmental protection - Electromagnetic radiation monitoring instruments and methods
HJ 1212 Measurement methods for determination of radon in environmental air
JGJ/T 309 The standard of the measurement and evaluation for efficiency of building ventilation
ISO 7726 Ergonomics of the thermal environment - Instruments for measuring physical quantities
ISO/TS 14415:2005 Ergonomics of the thermal environment - Application of International Standards to people with special requirements
3 Terms and definitions
No terms and definitions are listed in this document.
4 Air temperature
4.1 Liquid-in-glass thermometer method
4.1.1 Principle
The liquid-in-glass thermometer is composed of a thin-walled temperature sensing bulb containing the thermometer liquid and a thin glass tube sealed and connected with the temperature sensing bulb. The change of air temperature will cause the temperature change of the temperature sensing bulb, and the liquid volume in the temperature sensing bulb will change accordingly. When the temperature of the temperature sensing bulb increases, the liquid expands and the liquid column in the thin tube rises; and vice versa. The thin glass tube is graduated to indicate the height of the liquid column inside the tube, and the liquid column height reading accurately indicates the temperature of the temperature sensing bulb.
4.1.2 Instruments
The instruments used in this method are as follows:
——Liquid-in-glass thermometer (minimum scale division not exceeding 0.2°C, measurement accuracy ±0.5°C);
——Thermometer hanging bracket.
4.1.3 Measurement procedures
Measurement procedures shall be carried out as follows:
a) The layout of measuring points shall comply with the provisions of A.2, Annex A;
b) Readings shall be taken after 5 minutes. When taking readings, first read the decimal part and then the integer. The line of sight shall be perpendicular to the thermometer scale. For mercury thermometers, readings shall be taken at the highest point of the convex surface; for alcohol thermometers, readings shall be taken at the lowest point of the concave surface.
c) Readings shall be taken quickly and accurately to avoid the influence of human breath on the accuracy of the readings;
d) Due to the thermal after-effect of glass, the zero point position of the liquid-in-glass thermometer shall be frequently calibrated with a standard thermometer. If there is a displacement at the zero point, the displacement value shall be added to the reading;
e) When exposed to sunlight or other thermal radiation, the temperature sensing bulb shall be shielded from heat when necessary to prevent contact with body parts such as hands.
4.1.4 Result calculation
Temperatures shall be calculated using Equations (1) and (2).
tactual = tmeasured + d (1)
where,
tactual——the actual temperature, °C.
tmeasured——the measured temperature, °C.
d——the zero displacement value, °C.
d = a - b (2)
where,
a——the zero point shown by thermometer;
b——the zero point position of standard thermometer calibration.
4.1.5 Result expression
The measurement result of an area is given as the arithmetic mean of the measured values of the measuring points in the area.
4.1.6 Measuring range
Air temperature: -0°C ~ 50°C.
4.2 Digital display thermometer
4.2.1 Principle
PN junction thermistor, thermocouple, platinum resistor, etc. are used as the temperature sensor of the thermometer. The sensors generate electrical signals in response to temperature changes, which are then amplified and converted by an A/D converter before being directly displayed by the display as air temperature.
4.2.2 Instrument
Digital display thermometer: minimum resolution of 0.1°C, measurement accuracy of ±0.5°C.
4.2.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) Perform in-service verification and pre-use calibration of the instrument as required;
b) The arrangement of measuring points is in accordance with the provisions of A.2;
c) Operate the instrument in accordance with the instrument manual;
d) Read the temperature value after the reading on the display stabilizes.
4.2.4 Measuring range
Air temperature: 0°C ~ 50°C;
5 Relative humidity
5.1 Resistance capacitance method
5.1.1 Principle
Humidity is measured by utilizing the characteristic of moisture-sensitive elements, whose resistance and capacitance values change according to a certain pattern in response to changes in environmental humidity.
5.1.2 Instruments
Various hygrometers using resistive or capacitive humidity sensors (at 25°C, the maximum allowable error is not greater than ±5%).
5.1.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) The arrangement of measuring points is in accordance with the provisions of A.2;
b) The instrument is operated according to the instruction manual, and the relative humidity value is directly read out after the indicated value of the instrument is stable;
c) The humidity-sensitive part of the humidity sensor of the instrument shall not be touched by hands, and shall be protected from dust pollution, harmful gas corrosion or condensation.
5.1.4 Measuring range
Under conditions of 0°C ~ 60°C, the measurement range of a resistive hygrometer is 10% to 90%, while that of a capacitive hygrometer is 0% to 100%.
5.2 Dry and wet bulb method
5.2.1 Principle
Two identical mercury thermometers are installed in metal sleeves, and the ball part of the mercury thermometers has double radiation protection tubes. The top of the set is equipped with a fan driven by clockwork or electricity. Once activated, the fan draws air evenly through the sleeve, exposing the bulb to an airflow of ≥2.5 m/s (up to 3 m/s for electric models). The temperature of the dry and wet bulb thermometers is then measured, and the relative humidity of the air is calculated based on the temperature difference between the two thermometers.
5.2.2 Instruments
The instruments used in this method are as follows:
——Mechanical ventilation psychrometer: the minimum division of the temperature scale is not greater than 0.2°C, and the measurement accuracy is ±3%;
——Electric ventilation psychrometer: the minimum score of the temperature scale is not greater than 0.2°C, and the measurement accuracy is ±3%.
5.2.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) The arrangement of measuring points is in accordance with the provisions of A.2;
b) Correction of the working time of the ventilator of mechanical ventilation psychrometer: operate according to the instruction manual, and the total working time of the ventilator shall not be less than 6 min.
Contents
Foreword i
Introduction i
1 Scope
2 Normative references
3 Terms and definitions
4 Air temperature
5 Relative humidity
6 Wind speed (electronic anemometer method)
7 Fresh air volume
8 Noise (digital sound level meter method)
9 Illuminance (illuminance meter method)
10 Natural daylight factor
11 Atmospheric pressure (barometer method)
12 Radiant heat
13 Thermal comfort
14 Electromagnetic radiation (broadband omnidirectional field strength meter method)
15 Ultraviolet radiation (ultraviolet spectrum analysis dosimetry method)
16 Radon concentration in the air
17 Pool water temperature (thermometer method)
18 Pool water transparency
Annex A (Normative) Requirements for on-site detection sampling points
Annex B (informative) Environmental background and toxicity levels of tracer gases
GB/T 18204.1-2025 Examination methods for public places – Part 1: Physical indicators
1 Scope
This document describes the methods for measuring physical indicators in public places.
This document is applicable to the measurement of physical indicators in public places. Other places, such as residential rooms and other indoor environments, should refer to this document for guidance.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 18049 Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria
GB/T 18883 Standards for indoor air quality
HJ/T 10.2 Guideline on management of radioactive environmental protection - Electromagnetic radiation monitoring instruments and methods
HJ 1212 Measurement methods for determination of radon in environmental air
JGJ/T 309 The standard of the measurement and evaluation for efficiency of building ventilation
ISO 7726 Ergonomics of the thermal environment - Instruments for measuring physical quantities
ISO/TS 14415:2005 Ergonomics of the thermal environment - Application of International Standards to people with special requirements
3 Terms and definitions
No terms and definitions are listed in this document.
4 Air temperature
4.1 Liquid-in-glass thermometer method
4.1.1 Principle
The liquid-in-glass thermometer is composed of a thin-walled temperature sensing bulb containing the thermometer liquid and a thin glass tube sealed and connected with the temperature sensing bulb. The change of air temperature will cause the temperature change of the temperature sensing bulb, and the liquid volume in the temperature sensing bulb will change accordingly. When the temperature of the temperature sensing bulb increases, the liquid expands and the liquid column in the thin tube rises; and vice versa. The thin glass tube is graduated to indicate the height of the liquid column inside the tube, and the liquid column height reading accurately indicates the temperature of the temperature sensing bulb.
4.1.2 Instruments
The instruments used in this method are as follows:
——Liquid-in-glass thermometer (minimum scale division not exceeding 0.2°C, measurement accuracy ±0.5°C);
——Thermometer hanging bracket.
4.1.3 Measurement procedures
Measurement procedures shall be carried out as follows:
a) The layout of measuring points shall comply with the provisions of A.2, Annex A;
b) Readings shall be taken after 5 minutes. When taking readings, first read the decimal part and then the integer. The line of sight shall be perpendicular to the thermometer scale. For mercury thermometers, readings shall be taken at the highest point of the convex surface; for alcohol thermometers, readings shall be taken at the lowest point of the concave surface.
c) Readings shall be taken quickly and accurately to avoid the influence of human breath on the accuracy of the readings;
d) Due to the thermal after-effect of glass, the zero point position of the liquid-in-glass thermometer shall be frequently calibrated with a standard thermometer. If there is a displacement at the zero point, the displacement value shall be added to the reading;
e) When exposed to sunlight or other thermal radiation, the temperature sensing bulb shall be shielded from heat when necessary to prevent contact with body parts such as hands.
4.1.4 Result calculation
Temperatures shall be calculated using Equations (1) and (2).
tactual = tmeasured + d (1)
where,
tactual——the actual temperature, °C.
tmeasured——the measured temperature, °C.
d——the zero displacement value, °C.
d = a - b (2)
where,
a——the zero point shown by thermometer;
b——the zero point position of standard thermometer calibration.
4.1.5 Result expression
The measurement result of an area is given as the arithmetic mean of the measured values of the measuring points in the area.
4.1.6 Measuring range
Air temperature: -0°C ~ 50°C.
4.2 Digital display thermometer
4.2.1 Principle
PN junction thermistor, thermocouple, platinum resistor, etc. are used as the temperature sensor of the thermometer. The sensors generate electrical signals in response to temperature changes, which are then amplified and converted by an A/D converter before being directly displayed by the display as air temperature.
4.2.2 Instrument
Digital display thermometer: minimum resolution of 0.1°C, measurement accuracy of ±0.5°C.
4.2.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) Perform in-service verification and pre-use calibration of the instrument as required;
b) The arrangement of measuring points is in accordance with the provisions of A.2;
c) Operate the instrument in accordance with the instrument manual;
d) Read the temperature value after the reading on the display stabilizes.
4.2.4 Measuring range
Air temperature: 0°C ~ 50°C;
5 Relative humidity
5.1 Resistance capacitance method
5.1.1 Principle
Humidity is measured by utilizing the characteristic of moisture-sensitive elements, whose resistance and capacitance values change according to a certain pattern in response to changes in environmental humidity.
5.1.2 Instruments
Various hygrometers using resistive or capacitive humidity sensors (at 25°C, the maximum allowable error is not greater than ±5%).
5.1.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) The arrangement of measuring points is in accordance with the provisions of A.2;
b) The instrument is operated according to the instruction manual, and the relative humidity value is directly read out after the indicated value of the instrument is stable;
c) The humidity-sensitive part of the humidity sensor of the instrument shall not be touched by hands, and shall be protected from dust pollution, harmful gas corrosion or condensation.
5.1.4 Measuring range
Under conditions of 0°C ~ 60°C, the measurement range of a resistive hygrometer is 10% to 90%, while that of a capacitive hygrometer is 0% to 100%.
5.2 Dry and wet bulb method
5.2.1 Principle
Two identical mercury thermometers are installed in metal sleeves, and the ball part of the mercury thermometers has double radiation protection tubes. The top of the set is equipped with a fan driven by clockwork or electricity. Once activated, the fan draws air evenly through the sleeve, exposing the bulb to an airflow of ≥2.5 m/s (up to 3 m/s for electric models). The temperature of the dry and wet bulb thermometers is then measured, and the relative humidity of the air is calculated based on the temperature difference between the two thermometers.
5.2.2 Instruments
The instruments used in this method are as follows:
——Mechanical ventilation psychrometer: the minimum division of the temperature scale is not greater than 0.2°C, and the measurement accuracy is ±3%;
——Electric ventilation psychrometer: the minimum score of the temperature scale is not greater than 0.2°C, and the measurement accuracy is ±3%.
5.2.3 Measurement procedures
The measurement procedures shall be carried out as follows:
a) The arrangement of measuring points is in accordance with the provisions of A.2;
b) Correction of the working time of the ventilator of mechanical ventilation psychrometer: operate according to the instruction manual, and the total working time of the ventilator shall not be less than 6 min.
Contents of GB/T 18204.1-2025
Contents
Foreword i
Introduction i
1 Scope
2 Normative references
3 Terms and definitions
4 Air temperature
5 Relative humidity
6 Wind speed (electronic anemometer method)
7 Fresh air volume
8 Noise (digital sound level meter method)
9 Illuminance (illuminance meter method)
10 Natural daylight factor
11 Atmospheric pressure (barometer method)
12 Radiant heat
13 Thermal comfort
14 Electromagnetic radiation (broadband omnidirectional field strength meter method)
15 Ultraviolet radiation (ultraviolet spectrum analysis dosimetry method)
16 Radon concentration in the air
17 Pool water temperature (thermometer method)
18 Pool water transparency
Annex A (Normative) Requirements for on-site detection sampling points
Annex B (informative) Environmental background and toxicity levels of tracer gases
