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JJG 620-2008 English PDF

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JJG 620-2008: Verification Regulation of Critical Flow Venturi Nozzle
Status: Valid

JJG 620: Evolution and historical versions

Standard ID	Contents [version]	USD	STEP2	[PDF] delivered in	Standard Title (Description)	Status	PDF
JJG 620-2008	English	899	Add to Cart	6 days [Need to translate]	Verification Regulation of Critical Flow Venturi Nozzle	Valid	JJG 620-2008
JJG 620-1994	English	599	Add to Cart	4 days [Need to translate]	Verification Regulation of Critical Flowmeter	Obsolete	JJG 620-1994
JJG 620-1989	English	RFQ	ASK	3 days [Need to translate]	Vertey shedding Flow Transducer	Obsolete	JJG 620-1989

PDF similar to JJG 620-2008

Standard similar to JJG 620-2008

GB/T 36126 JJG 646 GB/T 1885 JJG 159 JJG 126 JJG 621

Basic data

Standard ID	JJG 620-2008 (JJG620-2008)
Description (Translated English)	Verification Regulation of Critical Flow Venturi Nozzle
Sector / Industry	Metrology & Measurement Industry Standard
Classification of Chinese Standard	A53
Classification of International Standard	17.120
Word Count Estimation	39,342
Date of Issue	2008-05-23
Date of Implementation	2008-11-23
Older Standard (superseded by this standard)	JJG 620-1994
Quoted Standard	JJF 1001-1998; JJF 1004-2004; JJF 1059-1999
Adopted Standard	ISO 9300-2005, NEQ
Regulation (derived from)	?AQSIQ Announcement 2008 No.72
Issuing agency(ies)	General Administration of Quality Supervision, Inspection and Quarantine
Summary	This standard applies to standard vertex refractometer (including objective standards analog eye, subjective standards simulated eye, cylinder standard device, refractor IPD standard device) initial verification, follow-up tests and in-service inspection.

JJG 620-2008: Verification Regulation of Critical Flow Venturi Nozzle

---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.
Verification Regulation of Critical Flow Venturi Nozzle State verification procedures People's Republic of China Critical flow Venturi nozzle Posted 2008-05-23 2008-11-23 implementation The State Administration of Quality Supervision, Inspection and Quarantine released Critical flow Venturi nozzle test procedures Replacing JJG 620-1994 The regulations by the State Administration of Quality Supervision, Inspection and Quarantine approved on May 23, 2008, and from From November 23, 2008 into effect. Focal point. the National Technical Committee on Metering flow capacity The main drafting units. China Institute of Metrology Participated in the drafting. the National Water flow metering station Large Yuyao Yinhuan Traffic Instrument Co., Ltd. Automation Instrumentation Co., Ltd. Tianjin Runtai Dandong blue letter Electric Co., Ltd. Zhejiang Institute of Quality and Technical Supervision and Inspection Shanghai Institute of Industrial Automation Instrumentation This procedure flow capacity commissioned the National Technical Committee responsible for the interpretation of measurement The main drafters of this procedure. Xu Yinghua (China Institute of Metrology) Drafters participate. Since Wang and (National Water flow metering station large) Zhu Jiashun (Yuyao Yinhuan Traffic Instrument Co., Ltd.) Li Chunhui (China Institute of Metrology) Children come again (Tianjin Runtai Automation Instrumentation Co.) Lidong Jun (Dandong blue letter Electric Co., Ltd.) Shen Wenxin (Zhejiang Quality and Technical Supervision and Inspection Institute) Guo Aihua (Shanghai Industrial Automation Instrument Research Institute)

1 Scope (1) 2. Referenced Documents (1) 3 Terms and Definitions (1) Symbols 4 (3) 5 Overview (5) Principle 5.1 (5) Installation 5.2 nozzle (5) 5.3 The basic equation (5) 6 metering performance requirements (6) 6.1 nozzle discharge coefficient accuracy class (6) Repeatability 6.2 discharge coefficient (6) 7 General Requirements (6) 7.1 appearance requirements and accompanying documents (6) 7.2 Uniform Requirements nozzle (6) Special requirements 7.3 nozzle (7) 7.4 critical flow function C * and the actual gas flow rate in CR critical computing (9) 8 measuring instruments control (9) 8.1 Verification condition (9) 8.2 Verification Project (9) 8.3 Verification Methods (10) 8.4 Arbitration (12) 8.5 test results processing (12) 8.6 test cycle (12) Appendix A of the nozzle discharge coefficient (13) Appendix B Common critical gas flow function C * value table (15) Appendix C to calculate the critical mass flux of gas mixture (22) Appendix D atmospheric air mass flow rate correction factor (26) Appendix E to the upstream pipe nozzle throat diameter ratio β > 0.25 the critical flow nozzle critical mass flux Calculation (27) Appendix F nozzle installation requirements (30) Calculation methods and the back pressure than the critical pressure ratio area Appendix G ratio A2A Relationship (33) Appendix H test certificate and test results in the notice page (34) Critical flow Venturi nozzle test procedures This procedure reference ISO 9300.2005 (E) Measurementofgasflowbymeansofcriticalflow Venturinozzles.

1 Scope

The order applies to the critical flow venturi nozzle and diffuser exit without measuring gas flow of critical flow nozzle Initial verification, subsequent verification and in-service inspection.

2 Citations

The provisions of the following standards, procedures included by reference, constitute provisions of this Directive. JJF1001-1998 common measurement terms and definitions JJF1004-2004 flow measurement terminology and definitions JJF1059-1999 Evaluation and Expression of Uncertainty in Measurement When using this procedure, it should pay attention to using the currently valid version of the documents cited.

3 Terms and Definitions

3.1 Static pressure staticpressure Actual pressure measured by the manometer is connected to the wall of the hole to take pressure to get the flow of gas. Note. Static pressure used in this protocol are absolute. 3.2 Static Temperature statictemperature The actual temperature is not affected by the air flow velocity of the flowing gas. NOTE. Static temperature used in this procedure are Kelvin temperature value. 3.3 stagnation state stagnationstate Fluid flow stagnation down state is reached when the velocity is zero. 3.4 stagnation pressure stagnationpressure Pressure gas stagnation state dead center. NOTE. stagnation pressure used in this protocol are absolute stagnation pressure only. 3.5 stagnation temperature stagnationtemperature Gas temperature stagnation state dead center. NOTE. stagnation temperature of the present regulations are used Kelvin temperature value. 3.6 isentropic index isentropicexponent Reversible adiabatic (isentropic) process, the ratio of the relative change of the relative change in pressure and density. Note 1. The isentropic exponent is given by. κ = ρp dp ρ S = Ρc

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