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JJF 1949-2021 English PDF

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US$329.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
JJF 1949-2021: Calibration Specification for Water Hardness Meters
Status: Valid

Standard ID	USD	BUY PDF	Lead-Days	Standard Title (Description)	Status
JJF 1949-2021	329	Add to Cart	3 days	Calibration Specification for Water Hardness Meters	Valid

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Basic data

Standard ID: JJF 1949-2021 (JJF1949-2021)
Description (Translated English): Calibration Specification for Water Hardness Meters
Sector / Industry: Metrology & Measurement Industry Standard
Word Count Estimation: 14,177
Issuing agency(ies): State Administration for Market Regulation

JJF 1949-2021: Calibration Specification for Water Hardness 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.
Calibration Specification for Water Hardness Meters National Metrology Technical Specification of the People's Republic of China Specification for calibration of water hardness tester Published on 2021-12-28 2022-06-28 Implementation Released by the State Administration for Market Regulation Specification for calibration of water hardness tester Focal Point. National Technical Committee of Environmental Chemical Metrology Main drafting unit. Guangzhou Institute of Metrology and Testing Technology Gansu Metrology Research Institute Shanghai Institute of Metrology and Testing Technology Participating in the drafting unit. Suzhou Metrology and Testing Institute Sun Yat-Sen University This specification is entrusted to the National Environmental Chemical Metrology Technical Committee to be responsible for the interpretation The main drafters of this specification. He Xin (Guangzhou Institute of Metrology and Testing Technology) Yang Juntao (Gansu Metrology Research Institute) Dai Hong (Guangzhou Institute of Metrology and Testing Technology) Meng Jiaoran (Shanghai Institute of Metrology and Testing Technology) Participating drafters. Shi Liyu (Gansu Metrology Research Institute) Zhang Chengchun (Suzhou Metrology and Testing Institute) Tang Minran (Sun Yat-sen University)

Introduction (Ⅱ) 1 Scope(1) 2 References (1) 3 Overview(1) 4 Metrology Characteristics(1) 4.1 Indication error of water hardness (1) 4.2 Repeatability(1) 4.3 Temperature indication error(1) 5 Calibration Conditions(1) 5.1 Environmental conditions (1) 5.2 Measuring instruments and ancillary equipment for calibration (2) 6 Calibration items and calibration methods (2) 6.1 Error of water hardness indication (2) 6.2 Repeatability(2) 6.3 Temperature indication error (3) 7 Expression of calibration results (3) 8 Recalibration interval(3) Appendix A Standard Solution Preparation Method(4) Appendix B Calibration Raw Record Format (Recommended) (5) Appendix C Calibration Certificate Inner Page Format (Recommended) (6) Appendix D Example of Measurement Uncertainty of Water Hardness Indication Error (7)

Introduction

This specification is based on JJF 1001-2011 "General Metrology Terms and Definitions", JJF 1071-2010 "National Metrology" Calibration Specification Compilation Rules" and JJF 1059.1-2012 "Measurement Uncertainty Evaluation and Representation", refer to Tested GB 8538-2016 "National Food Safety Standard Drinking Natural Mineral Water Inspection Method", GB/T 6909- 2018 "Determination of Hardness of Boiler Water and Cooling Water Analysis Method" and ASTMD1126-2017 "Standard of Water Hardness" This specification is published for the first time. Specification for calibration of water hardness tester

1 Scope

This specification applies to the calibration of benchtop and portable water hardness testers whose measuring principle is the colorimetric or electrode method.

2 Reference documents

This specification references the following documents. GB/T 6682 Analysis Laboratory Water Specifications and Test Methods For dated references, only the dated version applies to this specification; for undated references The latest version (including all amendments) applies to this specification.

3 Overview

The total water hardness mainly refers to the total content of calcium ions and magnesium ions in the water body, of which calcium hardness is caused by calcium ions. Magnesium hardness is caused by magnesium ions, and its common measurement units are molar concentration mmol/L or mass concentration mg/L (as CaCO3, CaO or Ca). Water hardness tester (hereinafter referred to as hardness tester) is mainly used in food, medicine, environmental protection, chemical industry and other fields Measurement of water hardness. The hardness tester is roughly divided into two categories according to the measurement principle. One is the principle of colorimetry. calcium in water samples, Magnesium ions react with a color developer to form a compound of a specific color, and the absorbance value of the compound is similar to that of a specific wavelength. The concentration of calcium and magnesium ions is related, and the water hardness value is obtained by measuring the absorbance value. The colorimetric hardness tester is mainly composed of a light source, a sample It is composed of a product room, a detection unit and a data processing unit. The other is the principle of the electrode method. the use of ion-selective electrodes for The relationship between the electrode potential and the water hardness content conforms to the thermodynamic Nernst equation. water hardness value. Electrode hardness tester is mainly composed of electrodes, electronic units and (or) display units.

4 Metrology characteristics

4.1 Indication error of water hardness Colorimetric hardness tester water hardness indication error. no more than ±10%. The error of water hardness indication value of electrode method hardness tester. no more than ±15%. 4.2 Repeatability Colorimetric hardness tester repeatability. ≤3%. Electrode method hardness tester repeatability. ≤5%. 4.3 Temperature indication error Temperature indication error does not exceed ± 0.5 ℃. Note. The above measurement characteristics requirements are for reference only, not as a basis for judgment.

5 Calibration Conditions

5.1 Environmental conditions ......

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Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of JJF 1949-2021_English be delivered?

Answer: Upon your order, we will start to translate JJF 1949-2021_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of JJF 1949-2021_English with my colleagues?

Answer: Yes. The purchased PDF of JJF 1949-2021_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.