This standard specifies the scattered light method for the determination of turbidity in industrial circulating cooling water. This standard applies to the determination of turbidity in industrial circulating cooling water, with a measurement range of 0 to 50 FNU. GB/T 15893.1-1995 Determination of turbidity in industrial circulating cooling water by scattered light method GB/T15893.1-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of turbidity in industrial circulating cooling water
Scattered light method
Industrial circulating cooling water-- Determination of turbidity --Diffused radiation methodThis standard is not equivalent to the international standard ISO7027-1990 "Determination of turbidity of water quality". 1 Subject content and scope of application
This standard specifies the scattered light method for the determination of turbidity in industrial circulating cooling water. This standard is applicable to the determination of turbidity in industrial circulating cooling water, with a measurement range of 0 to 50 FNU. 2 Reference standards
GB/T6682 Specifications and test methods for water used in analytical laboratories 3 Summary of methods
GB/T15893.1-1995
This standard uses Formazin polymer as the turbidity standard reference solution and uses a turbidity meter based on the scattered light principle to determine the turbidity of water samples.
4 Reagents and Materials
The water used in this standard is the secondary water specified in GB/T 6682. The reagents used are analytically pure reagents unless otherwise specified. 4.1 Formazin Standard Turbidity Stock Solution
4.1.1 Solution A: Weigh 10.00±0.01g hexamethylenetetramine (GB/T1400), dissolve it in water, and dilute to 100ml. 4.1.2 Solution B: Weigh 1.000±0.001g hydrazine sulfate (GB/T698), dissolve it in water, and dilute to 100ml4.1.3 Use a pipette to transfer 5mL of solution A and 5mL of solution B, mix them, place them at 25±3℃ for 24h, and then dilute them to 100ml with water. The turbidity of this formazin solution is 400FNU. The solution is stored in a dark place at 25±3℃ and is stable for four weeks. 4.2 Formazine standard reference solution
Use a pipette to transfer a certain volume of formazine solution (4.1.3) and dilute it with water in a volumetric flask of a certain volume to prepare a formazine standard reference solution of the required turbidity. The stability period of this solution is one week. 5 Instruments and equipment
5.1 Scattered light turbidimeter:
5.1.1 Light source: Tungsten filament lamp operating at a color temperature of 2200~~3000K. 5.1.2 The total distance that the scattered light of the incident light passes in the water sample test tube should not exceed 10cm. 5.1.3 Detector: The angle of receiving light is concentrated at 90°±30° relative to the light path of the incident light. Approved by the State Administration of Technical Supervision on December 20, 1995, and implemented on August 1, 1996
GB/T15893.1—1995
5.2 Slow quantitative filter paper or glass sand core funnel with a pore size of 2~5um. 6 Analysis steps
6.1 Debugging
Debug the instrument according to the turbidity meter manual. bzxZ.net
6.2 Positioning
Select a formazin standard reference solution whose turbidity value is close to that of the water sample to be tested. Repeat zeroing and positioning until it is stable. 6.3 Determination
6.3.1 Shake the water sample and wait for the bubbles to disappear. Inject the water sample into the test tube of the turbidity meter for determination, and read the turbidity value directly from the instrument. 6.3.2 If the water sample has a large chromaticity, filter the water sample after the test through a slow quantitative filter paper or a glass sand core funnel with a pore size of 2 to 5um, and then measure the filtered water sample. The turbidity of the water sample to be tested is the result of subtracting the measured value of the filtered water sample from the measured value of the original water sample. 7 Expression of analysis results
Report the results in formalin units (FNU) 8 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results: when the turbidity is less than 1FNU, it is not more than 0.05FNU; when the turbidity is 1~10FNU, it is not more than 0.2FNU; when the turbidity is 10~50FNU, it is not more than 0.5FNU. Additional remarks:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard is drafted by Guangming Chemical Research Institute of the Ministry of Chemical Industry and Xiamen Feihua Environmental Protection Equipment Factory. The main drafters of this standard are Guo Ximin, Du Maoxian, Cai Kangyu, Da Xi and Zhu Chunyue. From the date of promulgation of this standard, the departmental standard HG5-1503-85 "Measurement Method of Turbidity in Industrial Circulating Cooling Water" issued by the former Ministry of Chemical Industry of the People's Republic of China will be invalidated.
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