This standard specifies the humidity conditioning before and during the testing of the physical or mechanical properties of textiles. GB 6529-1986 Standard atmosphere for humidity conditioning and testing of textiles GB6529-1986 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Standard atmospheres for textiles conditioning and testing This standard adopts the international standard ISO139-1973 "Textiles-UDC 677.01
GB 6529-86
Standard atmospheres for far conditioning and testing" (ISO139-1973 Textiles-Standard atmospheres far conditioning and testing), and supplements the following contents: Appendix A "Method for determination of relative humidity of the atmosphere", Appendix B "Relative humidity table of aspirated Assmann hygrometer", Appendix C "Outdoor atmospheric pressure in major cities in my country". Scope of application
This standard specifies the atmospheric conditions for conditioning before and during the determination of physical or mechanical properties of textiles. 2 Basic definitions
2.1 Relative humidity
The ratio of the actual water vapor pressure of the atmosphere to the saturated water vapor pressure at the same temperature, usually expressed as a percentage. 2.2 Temperate standard atmosphere
Atmosphere with a temperature of 20°C and a relative humidity of 65%. 2.3 Tropical standard atmosphere
Atmosphere with a temperature of 27°C and a relative humidity of 65%. 2.4 Temperate standard atmosphere for testing
First-level standard: atmosphere with a temperature of 20±2°C and a relative humidity of 65±2%. Second-level standard: atmosphere with a temperature of 20±2°C and a relative humidity of 65±3%. Third-level standard: atmosphere with a temperature of 20±2°C and a relative humidity of 65±5%. 2.5 Tropical standard atmosphere for testing
First-level standard: atmosphere with a temperature of 27±2°C and a relative humidity of 65±2%. Second-level standard: atmosphere with a temperature of 27±2°C and a relative humidity of 65±3%. Third-level standard: atmosphere with a temperature of 27±2°C and a relative humidity of 65±5%. Note: The two modifiers "temperate" and "tropical" used in this standard are only applicable to the textile industry. 3 Pre-humidification
In order to allow the textile to reach humidity equilibrium in the hygroscopic state during the humidity conditioning period, pre-humidification may be required. To achieve this, the textile should be placed in an atmosphere with a relative humidity of 10-25% and a temperature not exceeding 50°C to approach equilibrium. The above atmospheric conditions can be obtained by heating air with a relative humidity of 65% and a temperature of 20°C to 50°C, or by heating air with a relative humidity of 65% and a temperature of 27°C to 50°C. 4 Humidification
Before determining the physical or mechanical properties of the textile, it should be placed in a temperate standard atmosphere for humidity conditioning. During the humidity conditioning period, air should be allowed to flow through the textile unimpeded until it reaches equilibrium with the air. Issued by the State Bureau of Standards on June 25, 1986
Implemented on March 1, 1987
GB 652986
Unless otherwise specified in the test method for textiles, textiles freely exposed to the flowing air under the above conditions can be considered to have reached equilibrium only when the mass (weight) variation of continuous weighing every 2 hours does not exceed 0.25%. Alternatively, the equilibrium state can also be considered to have been reached when the mass variation of continuous weighing every 30 minutes does not exceed 0.1%. In case of dispute, the former shall prevail. In tropical areas, the tropical standard atmosphere for testing can be used. 5 Tests
Except for special circumstances (for example, wet tests), the determination of physical and mechanical properties of textiles shall be in accordance with the provisions of the temperate standard atmosphere for testing. In tropical or subtropical areas, the tropical standard atmosphere for testing can be used. For arbitration tests, the first standard of the temperate standard atmosphere for testing shall be used. 6 Determination of relative humidity
The method for determining the relative humidity of the atmosphere is shown in Appendix A. For the relative humidity table of the aspirated Assmann hygrometer, see Appendix B. The values ​​given in Table B2 should be corrected according to the local outdoor atmospheric pressure. For the correction method, see the correction coefficients and their explanations given in Table B1. For the outdoor atmospheric pressure of major cities in my country, see Appendix C. 130
GB 6529-88
Appendix A
Method for determination of relative humidity of the atmosphere
(Supplement)
This determination method refers to the American Society for Testing and Materials standard ASTME337-62 (1979 review of "Standard test method for relative humidity by wet and dry-bulb psychrometer").
A.1 Scope of application
This method determines the relative humidity of the atmosphere using the readings of the dry-bulb mercury thermometer of the aspirated Assmann hygrometer. However, the determination method when the atmospheric temperature is below freezing is not included.A.2 Definitions
A.2.1 Dry-bulb temperature
The atmospheric temperature measured by a precision mercury thermometer with a graduation value and accuracy of 0.1°C. The measurement must avoid significant influence of thermal radiation factors.
A.2.2 Wet-bulb temperature
A precision mercury thermometer with a graduation value and accuracy of 0.1°C. Its bulb is wrapped with wet cotton or linen cloth. The installation and use of this thermometer are in accordance with the provisions of this method. The readings measured by this thermometer. A.8 Aspirated Aspergillus hygrometer
Using the above two thermometers, its detailed specifications The size must comply with the provisions of ZBY270--84 "Industrial Glass Thermometer and Laboratory Glass Thermometer", and be assembled with a motor and a small fan to provide airflow through the ball of the dry-bulb thermometer, and measure the relative humidity of the atmosphere with the dry-bulb temperature and the wet-bulb temperature.
The air-suction Assmann hygrometer can also be used as a standard instrument for calibrating other types of relative humidity meters. A.3.1 Encapsulation of the wet bulb
A.3.1.1 Cloth for encapsulation of the wet bulb
The cloth used to wrap the wet bulb thermometer ball is a tubular soft cotton or linen woven belt , the number of horizontal rows per centimeter is 5, the number of longitudinal rows per centimeter is 6, and the linear density of the weaving yarn is 48tex×2. This tubular wrapping cloth must be bleached, but not starched, clean and have good water absorption properties. For example. When absorbing water in a dry state in the vertical direction, the wetting distance can rise by 7cm within 15 minutes. A.3.1.2 Wrapping of the wet bulb
The above-mentioned tubular gauze must be used to wrap the ball of the wet-bulb thermometer tightly, but not too tight. The upper end of the tubular gauze should extend above the ball by three times the diameter of the thermometer rod to reduce the influence of the temperature on the wet-bulb temperature. The influence of heat transfer on the meter rod. After the thermometer ball is put into the tubular gauze, use cotton yarn to gently tighten the tubular gauze at the lower end of the ball and the neck above the ball. The end of the tubular gauze should be long enough to be immersed in the water reservoir. Rubber finger cots should be used when installing and wrapping the tubular gauze to avoid contamination and keep the gauze clean. A.3.2 Wet-bulb water
The tubular gauze should be soaked with distilled water. When used for high-precision measurements, the temperature of the distilled water in the water reservoir should be the same as or slightly higher than the wet-bulb temperature. This is especially necessary when the ambient temperature is high and the relative humidity is low. In most cases, the water temperature can be the same as or slightly lower than the room temperature.
Under normal temperature and without freezing, if distilled water is stored in a porous permeable porcelain cup, the water will automatically cool down to close to room temperature. A.3.3 Airflow
GB 6529--86
A.3.3.1 The thermometer should be installed in a way that prevents the air flowing through the wet bulb from contacting the dry bulb again. This air flow direction will cause errors in the reading of the dry bulb thermometer. To avoid this, the air should contact the dry bulb before flowing through the wet bulb, or the air flow can be divided into two parts, flowing through the dry bulb and the wet bulb respectively.
A.3.3.2 The airflow duct should be designed to provide the best airflow at the thermometer bulb, that is, the airflow velocity is at least 5m/s when the altitude of the measurement area is zero, and the airflow velocity increases by 3-4% for every 305m increase in altitude. A.3.3.3 The motor, fan and airflow duct should be designed so that the airflow flows directly through the thermometer bulb before contacting the motor, and should prevent the air from being sucked from the observer's face or body during observation. A.3.4 Radiation Shield
A thin cylindrical and stable radiation shield shall be installed on the periphery of the wet-bulb thermometer to prevent heat radiation from affecting the reading of the thermometer.
The distance from the lower end of the radiation shield to the lower end of the sphere shall not be less than d and not more than 3d, where d is the diameter of the wet bulb after being wrapped with tubular gauze. The inner and outer surfaces of all radiation shields shall be well polished to maintain a bright luster. The thickness of the metal sheet used for the shield is 0.4 to 0.8 mm.
A.3.4.1 Primary External Shield
The above-mentioned radiation shield concentric with the sphere shall be installed on the periphery of the sphere of the wet-bulb thermometer. A.3.4.2 Secondary wet bulb shield
The bulb of the wet bulb thermometer shall also be protected by a secondary shield, which is installed between the primary external shield and the wet bulb to eliminate the radiation and conduction sources caused by the dry-bulb and wet-bulb temperature differences. A.3.4.3 Design of radiation shield
The design of both radiation shields shall facilitate the wetting and replacement of the tubular gauze of the wet bulb thermometer. A.4 Alternative instruments
Unless there is a dispute, other instruments may be used to determine relative humidity. Provided that there is flowing air under the specified conditions at the sensitive element of the instrument, the indication of the instrument is proved to be equivalent to that of the standard aspirated Assmann hygrometer specified in this standard, and the instrument is carefully checked at sufficiently short intervals and its accuracy falls within the allowable range. A.5 Working procedures
A.5.1 Installation
The installation location of the instrument should avoid being near machinery, heat radiation from the sun or other radiation sources. It is best to place the instrument in a location where air flows past the operator before it contacts the instrument. The highest accuracy is achieved when the operator's clothing and skin have time to equilibrate with the room air before reading the instrument. A height gauge can also be used for observation to take readings at a longer distance. A.5.2 Instrument preparation
Fully moisten the thermometer's wet-bulb gauze with distilled water. For a new or dry wet-bulb gauze, it will take several minutes to completely saturate it. Avoid direct contact with the gauze with your fingers, which may be contaminated with oil. Replace contaminated tubular gauze and keep the dry bulb dry.
A.5.3 Instrument ventilation
Drive the fan motor so that the two thermometers are exposed to the air flow until the wet-bulb thermometers indicate the lowest temperature value. A.5.4 Instrument readings
After driving the fan, carefully read the readings of the two thermometers, reading the wet-bulb temperature first. Under normal circumstances, an error of 0.15°C in wet bulb temperature results in an error of about 1% in relative humidity. When reading the thermometer indication, objects that are at a different temperature from the ambient temperature, such as hands, faces, and other hot or cold objects, should be kept as far away from the sensitive mercury sphere as possible. A.5.5 Verification of readings
For verification purposes, take as many readings as possible until the difference in wet bulb drop values ​​between two of three consecutive readings is no more than 0.1°C. If air conditions are fluctuating, calculate the average value of several readings. 132
A.6 Calculation of results
GB 6529—86
A.6.1 Subtract the wet bulb temperature reading from the dry bulb temperature reading. This difference is called the "wet bulb temperature drop", or "wet bulb drop" for short. The observed dry bulb temperature and wet bulb drop are used to calculate the relative humidity from the basic equation of the hygrometer. In practice, direct calculation using the basic equation is rarely used, and tables, curves, or other calculation tools are mainly used. In this way, the relative humidity can be obtained conveniently and quickly, as long as the deviation between the result and the result calculated by the basic equation falls within the permissible range. A.6.2 Dry-bulb hygrometer equation:
e=e\-AP(t-t)
Where: e-
the partial pressure of water vapor in the atmosphere when the dry-bulb temperature is t, mmHg, e'-the saturated water vapor pressure when the atmospheric temperature is the wet-bulb temperature t', mmHg, P--atmospheric pressure, mmHg?
t-the difference in wet-bulb temperature, expressed in °C
-coefficient, A=6.60×10-4(1+0.00115t) (for water). (A1)
A.6.3 Relative humidity: The water vapor partial pressure value calculated by the dry-bulb hygrometer equation is then used to calculate the relative humidity by equation A2, or the relative humidity can be obtained by looking up the relative humidity in Appendix B.
rh - 100e/E..
Where: rh -
Relative humidity, %
Saturated water vapor pressure of the atmosphere at dry bulb temperature, mmHg. When using a standard aspirated Assmann hygrometer, the relative humidity shall be measured with an accuracy of 1%. A.6.4
GB6529—86
Appendix B
Relative humidity table for aspirated Assmann hygrometer (supplement)
When the atmospheric pressure is different from 99018.2Pa (742.7mmHg), the correction factor F for the relative humidity values ​​given in Table B2 is shown in Table B1. Table B1
Air temperature
Formula (B1)
5.4335×10-5
5. 0791 × 10- 5
4.7543 × 10~ s
4.4590 ×10-5
4.1932×10-5
3.9274×10-5
3.6912×10-5
3.4550 ×10-5bzxZ.net
3.2482 × 10- 5
3.0415×10-5
2.8732 × 10- 5
2.7049 ×10- 5
2.5454 × 10- 5
2.4007×10~5
2.2619×10-5
2.1320 ×10-5
2.0109 × 10 - 5
1.8987 × 10 - 5
1.7924 × 10 - 5
1.6920 × 10- 5
1.5916 ×10-5
1.5060 × 10 - 5
1.4233×10-5
1.3495×10- 5
1.2756 × 10- 5
1.2048 × 10- 5
1.1369×10-5
1.0778 × 10 - 5
1.0217×10-5
0.9715 × 10 - 5
0. 9213 × 10- 5
武(B2)
7.244 × 10-3
6.772 ×10~3
6.339 × 10-3
5.945 ×10-a
5.591×10-3
5.236×10-3
4.921 ×10-3
4.606 ×10-3
4.331×10-3
4.055×10-3
3.831 ×10-3
3.606×10-3
3.394×10-3
3.201×10-3
3.016×10-3
2.843×10-3
2.681 ×10-3
2.531×10-3
2.390 ×10-3
2.256×10- 3
2.122×10-3
2.008 ×10-3
1.898 × ​​10- 3
1.799×10-3
1.701×10-3
1.606 ×10-3
1.516×10-3
1.437 ×10-3
1.362×10-3
1.295×10-3
1.228×10-3
GB 6529—86
For the application of the correction factor F, see the following equation expressed in percentage: R. =R, +F(t -t)(99018.2- P)
R. = R, + F(t -t')(742.7 - P) where: Ra-
dry bulb temperature is t, wet bulb temperature is!, atmospheric pressure is P, actual relative humidity, (B1)
corresponds to temperature t and t-!, atmospheric pressure is 99018.2Pa (742.7mmHg), relative humidity given in Table B2
according to the observed value of dry bulb temperature t, correction factor given in Table B1. F
When P value is greater than 99018.2Pa (742.7mmHg), correction value is negative, when P value is less than 99018.2Pa (742.7mmHg), correction value is positive.
Example:
Example 1. t =30℃,tt* =6.5℃,
P= 103962Pa (779.78mmHg)
From Table B2, R1=58%; From Table B1, F=1.5916×10-5R.= 58% + 1.5916× 10-5 × 6.5 ×(99018.2 - 103962)%= 58% - 0.51% =58% - 1% = 57%Example 2. t = 40℃, 1-t*=17.8℃, P=79579.9Pa(596.9mmHg)From Table B2, R,=20%From Table B1, F=0.9213×10-5R. =20%+0.9213×10-5×17.8×(99018.2-79579.9)%=20% +3.19%20% + 3 % = 23%
Example 3. t=16℃, -1=4.5℃, Beijing area, winter P=102258Pa(767mmHg)
From Table B2, R,=58%, from Table B1, F=3.6912×10-5R, = 58% + 3.6912 × 10- 5 × 4.5 ×(99018.2 - 102258)%= 58% 0.54% ~ 57%
Example 4. t=20℃, t-1=4.2℃, Kunming area, winter P= 81193.1Pa(609mmHg)
From Table B2, R,=65%, from Table B1, F=2.8732×10-5R. =65% +2.8732×10-5×4.2 ×(99018.281193.1)%= 65% + 2.15% ~ 67%
Air temperature, ℃
GB 6529-86
2Relative humidity table B2 of suction type Assmann hygrometer
【99018.2Pa（742.7mmHg)]
Wet bulb temperature
Air temperature, ℃
GB 6529--86
Continued table B2
Air temperature t℃
GB 6529-86
Continued Table B2
Temperature drop
Air temperature t: ℃
GB 6529—86
Continued Table B2
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