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JJG 291-2018 English PDF

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JJG 291-2018: Dissolved Oxygen Meters
Status: Valid

JJG 291: Evolution and historical versions

Standard IDContents [version]USDSTEP2[PDF] delivered inStandard Title (Description)StatusPDF
JJG 291-2018English439 Add to Cart 4 days [Need to translate] Dissolved Oxygen Meters Valid JJG 291-2018
JJG 291-2008English170 Add to Cart 0--9 seconds. Auto-delivery Verification regulation of dissolved oxygen meter with covered-membrane-electrode Obsolete JJG 291-2008
JJG 291-1999English479 Add to Cart 4 days [Need to translate] Verification Regulation of Film Electrode Dissolved Oxygen Meter Obsolete JJG 291-1999
JJG 291-1982EnglishRFQ ASK 3 days [Need to translate] (Chinese Industry Standard) Obsolete JJG 291-1982

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Basic data

Standard ID JJG 291-2018 (JJG291-2018)
Description (Translated English) Dissolved Oxygen Meters
Sector / Industry Metrology & Measurement Industry Standard
Classification of Chinese Standard A61
Word Count Estimation 19,122
Date of Issue 2018-02-27
Date of Implementation 2018-08-27
Older Standard (superseded by this standard) JJG 291-2008
Regulation (derived from) AQSIQ Announcement No. 26 of 2018
Issuing agency(ies) General Administration of Quality Supervision, Inspection and Quarantine

JJG 291-2018: Dissolved Oxygen Meters

---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
(Dissolved Oxygen Tester Verification Procedure) National Metrology Verification Regulations of the People's Republic Dissolved oxygen analyzer Published on.2018-02-27 2018-08-27 implementation The General Administration of Quality Supervision, Inspection and Quarantine issued Dissolved oxygen analyzer calibration procedures Replace JJG 291-2008 Focal Point. National Environmental Chemometrics Technical Committee Main drafting unit. Zhejiang Institute of Metrology Shanghai Institute of Metrology and Testing Technology Participated in the drafting unit. China Institute of Metrology Beijing Aerospace Measurement and Testing Technology Research Institute Foshan Analyzer Co., Ltd. This procedure entrusts the National Environmental Chemometrics Technical Committee to explain The main drafters of this procedure. Lin Wei (Zhejiang Institute of Metrology) Xu Yuan (Zhejiang Institute of Metrology) Wang Zhentao (Shanghai Institute of Metrology and Testing Technology) Participate in the drafters. Xiu Hongyu (China Institute of Metrology) Zhang Wei (Zhejiang Institute of Metrology) Fu Jiale (Shanghai Institute of Metrology and Testing Technology) Feng Zhijun (Beijing Aerospace Measurement and Testing Technology Research Institute)

table of Contents

Introduction (III) 1 Scope (1) 2 Overview (1) 3 Metrological performance requirements (1) 3.1 Zero error (1) 3.2 Response time (1) 3.3 Dissolved oxygen concentration indication error (1) 3.4 Repeatability (1) 3.5 Temperature indication error (1) 3.6 Salinity compensation error (1) 4 General technical requirements (1) 4.1 Appearance and Structure (1) 4.2 Signs and logos (1) 5 measuring instrument control (2) 5.1 Verification conditions (2) 5.2 Verification project (2) 5.3 Verification method (3) 5.4 Processing of verification results (4) 5.5 Verification cycle (5) Appendix A Preparation of certified water (6) Appendix B Preparation and verification water device structure diagram (7) Appendix C Oxygen saturation concentration in water at different water temperatures and atmospheric pressures and interpolation method to calculate saturated dissolved oxygen concentration in water (8) Appendix D Dissolved Oxygen Analyzer Verification Record (11) Appendix E Format of the verification certificate/verification result notice (13)

Introduction

This procedure refers to HJ506-2009 "Electrochemical Probe Method for Determination of Dissolved Oxygen in Water", ISO 5814. 2012 Water Quality-Determinationof dissolvedoxygen-Electrochemicalprobemethod), ISO 17289.2014 "Water Dissolved Oxygen Water quality-Determination of dissolved oxygen-Opticalsensor Method) and other standards related content, according to JJF1002-2010 "National Metrology Verification Procedures Writing Rules" Written, compared with JJG 291-2008, in addition to editorial changes, the main content changes are as follows. --- Added introduction content; --- Revised the name of the procedure and the scope of application (see cover and scope 1); ---In the overview section, the measurement principle of the coated electrode dissolved oxygen analyzer and the fluorescent dissolved oxygen analyzer is added. Said (see 2 for an overview); --- Modified the "repetitive" metrology performance requirements (see 3.4); --- Removed "insulation resistance" and "insulation strength" technical requirements, verification items, equipment for verification and verification Method (see 4, 5.1, 5.2, 5.3); --- Modify the technical indicators such as the barometer index value in the standard and supporting equipment for verification, and increase the sodium chloride (NaCl) reagent purity requirements (see 5.1.2); --- Modified the "zero value error" verification method, extending the test time from "5min" to "15min", repair Changed the "response time" verification method (see 5.3.3, 5.3.4); --- Change the reference value of dissolved oxygen concentration to look-up table and interpolation method (see 5.3.5); --- Removed the "Saturation of Concentration Table of Oxygen at Different Temperatures" appendix in the original procedure and "Pure water at different temperatures" "Saturated Vapor Pressure" appendix adds "saturated concentration of oxygen in water at different water temperatures and atmospheric pressures" "Appendix" (see Appendix C). The previous versions of this procedure are released. ---JJG 291-2008; ---JJG 291-1999. Dissolved oxygen analyzer calibration procedures

1 Scope

This procedure applies to benchtop and portable dissolved oxygen meters with a measurement range of (0~20) mg/L (see below) The first verification, subsequent verification and in-use inspection of the instrument.

2 Overview

The instrument is primarily used to determine the concentration of dissolved oxygen (DO) in water. The instrument type mainly has a film electrode dissolved Oxygen analyzer and fluorescence dissolved oxygen meter. The measuring principle of the coated electrode dissolved oxygen analyzer is the electrochemical probe method. the oxygen sensitive membrane electrode is used to isolate water and Soluble matter, the potential difference between the electrodes causes the metal ions to enter the solution at the anode, while the oxygen diffuses through the membrane. Dispersed, reduced at the cathode, and the current produced is proportional to the rate of oxygen transmission through the membrane and electrolyte layer, ie at a certain The current is proportional to the partial pressure (or concentration) of oxygen in the water. Dissolved oxygen in water by measuring current concentration. The measurement principle of the fluorescent dissolved oxygen analyzer is mainly based on the quenching effect of oxygen molecules on fluorescent substances. in dissolution The electrode of the oxygen analyzer is coated with a fluorescent material, and the excitation light is irradiated on the electrode to emit fluorescence, and the fluorescence intensity or annihilation time is long. Short is related to the concentration of oxygen molecules in water; the higher the concentration of oxygen molecules in water, the smaller the fluorescence intensity, and the more annihilated fast. The dissolved oxygen concentration in the water can be obtained by measuring the phase difference between the excitation light and the reference light. The instrument typically consists of an oxygen electrode, an electronic unit, and/or a display unit.

3 Metrological performance requirements

3.1 Zero value error The zero value error of the instrument should not exceed 0.10mg/L. 3.2 Response time The response time of the instrument should not exceed 60s. 3.3 Dissolved oxygen concentration indication error The initial error of the dissolved oxygen concentration indication error of the instrument should not exceed ±0.30mg/L, and the subsequent verification should not exceed Over ±0.50mg/L. 3.4 Repeatability The repeatability of the instrument should not exceed 0.15 mg/L. 3.5 Temperature indication error The temperature indication error of the instrument should not exceed ±0.5 °C. 3.6 Salinity compensation error The salinity compensation error of the instrument should not exceed ±2%.

4 General technical requirements

4.1 Appearance and structure

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