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JJG 631-2013 PDF in English


JJG 631-2013 (JJG631-2013) PDF English
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JJG 631-2013English160 Add to Cart 0-9 seconds. Auto-delivery. Verification Regulation of Ammonia-Nitrogen Automatic Analyzers Valid
JJG 631-2004English519 Add to Cart 4 days Ammonia Analyzers Obsolete
JJG 631-1989English279 Add to Cart 3 days Verification Regulation for Ammonia Automatic Monitor Obsolete
Standards related to (historical): JJG 631-2013
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JJG 631-2013: PDF in English

JJG 631-2013 JJG National Metrological Verification Regulations of the People’s Republic of China Ammonia-Nitrogen Automatic Analyzers ISSUED ON. AUGUST 15, 2013 IMPLEMENTED ON. FEBRUARY 15, 2013 Issued by. General Administration of Quality Supervision, Inspection and Quarantine Verification Regulation of Ammonia-Nitrogen Automatic Analyzers Replacing JJG 631-2004 Administrative organization. National Environment Chemistry Metrology Technical Committee Main Drafting organizations. Shanghai Metrology and Testing Institute Jiangsu Province Metrology Institute Shanghai Electronics Scientific Instrument Co., Ltd. National Environment Chemistry Metrology Technical Committee is entrusted to be responsible for the explanation of this Regulation. Main drafters of this Regulation. Ding Min (Shanghai Metrology and Testing Institute) Gong Feiyan (Shanghai Metrology and Testing Institute) Xie Luyun (Shanghai Metrology and Testing Institute) Participating drafters of this Regulation. Cai Yeqiang (Jiangsu Province Metrology Institute) Xing Jinjing (Jiangsu Province Metrology Institute) Wang Qiaomei (Shanghai Electronics Scientific Instrument Co., Ltd.) Table of Contents Introduction ... 5 1 Scope ... 6 2 Overview ... 6 3 Measuring performance requirements ... 6 4 General technical requirements ... 7 5 Measuring instrument control ... 8 6 Processing of verification results ... 12 7 Verification cycle-time ... 12 Appendix A ... 13 Appendix B ... 14 Appendix C ... 17 Introduction This regulation is the revision to JJG 631-2004 "Ammonia automatic analyzers”. Compared with JJG 631-2004, in addition to editorial changes, the main technical changes are as follows. - Change the regulation’s name to "Ammonia-nitrogen automatic analyzers"; - The scope is extended from "applicable to ammonia automatic analyzers (gas sensing electrode method)" to "applicable to online ammonia-nitrogen automatic analyzers that is based on electrode method and Spectrophotometry (see Article 1); - Modify the instrument’s classification (see Article 3); - Modify indicated value error’s performance requirements (see Table 1); - Modify metrology device’s control requirements. Delete the requirements to new ex-factory instruments that all requirements must be verified according to Class A and Class B instruments (see Article 5); - Modify the list of verification items in metrology device control. Add item “response time” in “Use inspection” for electrode instrument (see Table 2); - Modify the standard substances’ concentrations which are used for verification of instrument’s indicated value error, stability, repeatability, and response time (see Articles 5.3.2, 5.3.3, 5.3.4, 5.3.5); - Modify the test result processing. Verification certificate is required to provide the qualified category (see Article 6). The historical version of JJG 631-2004 "Ammonia automatic analyzers" is. - JJG 631-1989 "Ammonia automatic analyzers". Ammonia-Nitrogen Automatic Analyzers 1 Scope This regulation applies to initial verification, subsequent verification, and use inspection of online ammonia-nitrogen automatic analyzers which is based on electrode method and spectrophotometry. 2 Overview Ammonia-nitrogen automatic analyzers can automatically and continuously monitor the ammonia-nitrogen concentration in water bodies such as groundwater, surface water, sewage, and industrial waste. Measurement methods of ammonia-nitrogen automatic analyzers (hereinafter referred to as the instrument) can be divided in electrode method and spectrophotometry. Spectrophotometry includes salicylic acid spectrophotometry and Nessler reagent spectrophotometry etc. Its principle is. after ammonia or ammonium ions in water reacts with the indicator reagent, it shows in color. At specific wavelength, the absorbance of the solution is proportional to the ammonia-nitrogen content, so as to achieve the quantitative analysis of ammonia-nitrogen in water sample. Electrode method includes gas- sensitive electrode method and ammonia ion selection method. Through measuring the electrode potential, the instrument obtains the ammonia- nitrogen content in the water sample. 3 Measuring performance requirements According the different use occasions of ammonia-nitrogen automatic analyzers, the instrument is divided into Class A and Class B. Class A instrument is used in occasion of low concentrations. Class B instrument is used in occasion of high concentrations. For those occasions using both classes, the instrument must meet all requirements of Class A and Class B. Measuring instrument’s performance requirements are shown in Table 1. 5.3.4 Stability In accordance with the instrument specifications and requirements, perform preheating stability and calibration to the instrument. For Class A instrument, use the ammonia-nitrogen standard solution with concentration of 2.0 mg/L to measure. For Class B instrument, use the ammonia-nitrogen standard solution with concentration of 25 mg/L to measure. Measure 1 time for each 0.5 h. Continuously measure for 4 h. According to formula (6), calculate the relative change amplitude of initial value for each measured value. Take the maximum absolute value as the verification result of instrument stability. Where. M - instrument stability, %; Ci – Instrument’s i-th measured value, mg/L; c0 - initial measured value, mg/L. 5.3.5 Response time The system is firstly cleaned with ammonia-free water. For Class A instrument, use the ammonia-nitrogen standard solution with concentration of 2.0 mg/L to measure. For Class B instrument, use the ammonia-nitrogen standard solution with concentration of 25 mg/L to measure. When the test solution enters into the instrument detection tank, it is as the starting point. Record the time when the instrument’s indicated value reaches the 90% of stable indicated value. Repeatedly measure for 3 times. Take the average value as the verification result of response time. 5.3.6 Safety performance 5.3.6.1 Insulation resistance Power plug is not connected to the grid. The power switch is at ON position. Use insulation resistance meter to apply 500 V d.c. test voltage between the power inlet-line and chassis. After it is stable for 5 s, measure the insulation resistance. 5.3.6.2 Insulation strength Power plug is not connected to the grid. The power switch is at ON position. Use voltage-withstand tester to respectively apply test voltage between the power inlet line and chassis. The test voltage is gradually increased to 1.5 kV, current-limit of 5 mA. Maintain for 1 min. Observe if there is arcing and C.2 Conclusion pages of verification certificate Certificate Number xxxxxx - xxxx Verification Result Tested items and verification result. Instrument category. Class A Class B S/N Verification item Verification result 1 Appearance 2 Indicated value error /(% or mg/L) 3 Repeatability /% 4 Stability /% 5 Response time/min 6 Insulation resistance/MΩ 7 Insulation strength 8 Leakage Current/mA (Blank) C.3 Conclusion pages of verification certificate Certificate Number xxxxxx - xxxx Verification Result Tested items and verification result. Instrument category. Class A Class B S/N Verification item Verification result 1 Appearance 2 Indicated value error /(% or mg/L) 3 Repeatability /% 4 Stability /% 5 Response time/min 6 Insulation resistance/MΩ 7 Insulation strength 8 Leakage Current/mA Unqualified item of verification result. (Blank) ......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.