JJG 971-2019 English PDFUS$399.00 · In stock
Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. JJG 971-2019: Liquid Level Gauges Status: Valid JJG 971: Historical versions
Basic dataStandard ID: JJG 971-2019 (JJG971-2019)Description (Translated English): Liquid Level Gauges Sector / Industry: Metrology & Measurement Industry Standard Classification of Chinese Standard: A53 Classification of International Standard: 17.100 Word Count Estimation: 17,177 Date of Issue: 2019 Date of Implementation: 2020-03-31 Issuing agency(ies): State Administration for Market Regulation JJG 971-2019: Liquid Level Gauges---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.Liquid Level Gauges National Measurement Verification Regulations of the People's Republic of China Level gauge Published on December 31,.2019 2020-03-31 Implementation Issued by the State Administration of Market Supervision and Administration Verification Regulation of Liquid Level Meter Replace JJG 971-2002 Centralized unit. National Pressure Measurement Technical Committee Main drafting unit. Shanghai Institute of Metrology and Testing Technology Participated in the drafting unit. Shanghai Xingshen Instrument Co., Ltd. Shanghai Instrument Automatic Control System Inspection and Testing Institute Co., Ltd. This regulation is entrusted to the National Pressure Measurement Technical Committee for interpretation The main drafters of this regulation. Tu Limeng (Shanghai Institute of Metrology and Testing Technology) Juan Lun Wang Can (Shanghai Institute of Metrology and Testing Technology) Participating drafters. Chen Yao (Shanghai Xingshen Instrument Co., Ltd.) Zhang Tianfei (Shanghai Institute of Metrology and Testing Technology) Guo Aihua (Shanghai Instrument and Control System Inspection and Testing Co., Ltd.) table of ContentsIntroduction (Ⅱ) 1 Scope (1) 2 References (1) 3 Terms and units of measurement (1) 4 Overview (1) 5 Measurement performance requirements (2) 5.1 Indication error (2) 5.2 Output value error (2) 5.3 Return difference (2) 5.4 Set point error (2) 5.5 Switching difference (2) 6 General technical requirements (2) 6.1 Appearance (2) 6.2 Pressure resistance and tightness (2) 6.3 Insulation resistance (3) 6.4 Dielectric strength (3) 7 Control of measuring instruments (3) 7.1 Verification conditions (3) 7.2 Verification items (4) 7.3 Verification method (5) 7.4 Processing of verification results (9) 7.5 Verification period (9) Appendix A Calibration Record Format of Level Gauge (10) Appendix B. Internal page format of the certificate of verification/certification result (12)IntroductionJJF1001 "General Metrology Terms and Definitions", JJF1002-2010 "Rules for Compiling National Metrology Verification Regulations", JJF1059.1-2012 "Measurement Uncertainty Evaluation and Expression" and other specifications, together constitute the basis for the revision of this regulation Basic series of specifications. Compared with JJG 971-2002 "Level Gauge", except for editorial changes, the main changes are as follows. --- According to the requirement that the introduction of JJF1002-2010 is a necessary content, the content of the introduction is added. --- Adjusted the term content. Removed the original three terms of “set point error”, “switching value” and “switching difference”. The two terms "level" and "level gauge" were added. --- In the overview part, the use occasion of the liquid level gauge is clearly defined. And according to the current industry habits, the liquid level measurement method is proposed Method, liquid level gauge measurement method, liquid level gauge installation method, liquid level gauge measurement principle and other four classification methods. --- The content of type evaluation has been deleted in the measurement performance requirements and general technical requirements. --- In the verification method, the horizontal liquid level simulation verification device is proposed, and the basic technical requirements are put forward. On the original Some vertical liquid level verification devices have raised new technical requirements. --- The verification process and requirements of the two devices are clarified in the verification method. --- Deleted the contents of Appendix A "Type Appraisal or Prototype Test Items and Test Methods" in the original regulations. --- Appendix B and Appendix C to the original regulations were modified accordingly. The release of previous versions of this regulation. --- JJG 971-2002. Verification Regulation of Liquid Level Meter1 ScopeThis regulation is applicable to the first verification, subsequent verification and in-use inspection of liquid level gauges (excluding radiation type liquid level gauges). The calibration of the level meter can refer to this regulation.2 Reference documentsThis regulation refers to the following documents. JJG 882 pressure transmitter For dated references, only the dated versions are applicable to this Regulation; for those without dates The latest version (including all amendments) is applicable to this regulation.3 Terms and units of measurement3.1 Terminology 3.1.1 Level The general term of liquid level, material level and interface (position) is a parameter reflecting the total amount of objects and the surface characteristics of materials. 3.1.2 Liquid level gauge Instruments used to indicate and control liquid levels and interfaces (positions) in industrial process measurement and control systems. 3.2 Unit of measurement The legal unit of measurement used by the level gauge is m (meter), or its decimal multiple unit. mm, cm, etc.4 OverviewThe liquid level gauge is widely used in the internal liquid level or interface of tanks, kettles, towers, bottles, furnaces, channels in industrial processes measuring. Liquid level measurement methods include visual method, manual throwing method, air blowing method, force measurement method, pressure method, electrical characteristic method, reflection Method, thermal method, radiation method, neutron method, etc. The liquid level gauge can be divided into contact type and non-contact type according to the measurement method. The level gauge can be divided into top-mounted, side-mounted, top-bottom, side-side, side-bottom, top-side, side Wall type. According to the measurement principle, the liquid level gauge can be divided into combined type, buoyancy type, pressure type, reflection type, and electrical characteristic type. Combined type. (quartz) glass tube level gauge, glass plate level gauge; Buoyancy type. magnetic turning column (plate) level gauge, magnetostrictive level gauge, servo level gauge, steel belt level gauge, (Electricity) float level gauge, float level gauge; Pressure type. static pressure (input) level gauge (transmitter), differential pressure level gauge (transmitter); Reflective. radar level gauge, ultrasonic level gauge, guided wave radar level gauge; Electrical characteristics. RF admittance level gauge, capacitance level gauge, etc. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of JJG 971-2019_English be delivered?Answer: Upon your order, we will start to translate JJG 971-2019_English as soon as possible, and keep you informed of the progress. The lead time is typically 2 ~ 4 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of JJG 971-2019_English with my colleagues?Answer: Yes. 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Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version JJG 971-2019 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. |