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JJF 1240-2010 English PDF

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JJF 1240-2010: Calibration Specification for Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles
Status: Valid

JJF 1240: Evolution and historical versions

Standard ID	Contents [version]	USD	STEP2	[PDF] delivered in	Standard Title (Description)	Status	PDF
JJF 1240-2010	English	399	Add to Cart	3 days [Need to translate]	Calibration Specification for Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles	Valid	JJF 1240-2010
JJF 1240-1990	English	199	Add to Cart	2 days [Need to translate]	O.T.N of the Primary Standard for the 1×1000N Force Standard Machine	Obsolete	JJF 1240-1990

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Basic data

Standard ID	JJF 1240-2010 (JJF1240-2010)
Description (Translated English)	Calibration Specification for Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles
Sector / Industry	Metrology & Measurement Industry Standard
Classification of Chinese Standard	A53
Classification of International Standard	17.120
Word Count Estimation	17,112
Date of Issue	2010-01-05
Date of Implementation	2010-04-05
Quoted Standard	GB/T 21188; JJG 620-2008; JJG 643-2003; JJF 1001-1998; JJF 1004-2004; JJF 1059-1999
Regulation (derived from)	AQSIQ Announcement No. 3 of 2010
Issuing agency(ies)	General Administration of Quality Supervision, Inspection and Quarantine
Summary	This standard applies to critical flow venturi nozzle method the gas flow standard device (hereinafter referred to as the device) during the calibration and verification.

JJF 1240-2010: Calibration Specification for Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles

---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 Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles People's Republic of China National Metrology Technical Specifications Critical flow Venturi nozzle Gas Flow Standards at Issued on. 2010-01-05 2010-04-05 implementation The State Administration of Quality Supervision, Inspection and Quarantine released Critical flow Venturi nozzle gas law Flow Standards at This specification by the State Administration of Quality Supervision, Inspection and Quarantine approved on January 5, 2010, and from From April 5, 2010 implemented. Focal point. the National Technical Committee on Metering flow capacity The main drafting units. China Institute of Metrology Participated in the drafting. Zhejiang Provincial Institute of Metrology Large national oil and gas flow metering stations Nanjing sub-station Liaoning Provincial Institute of Metrology Henan Institute of Metrology Dandong City-Bo Control Co., Ltd. This specification by the flow capacity of the National Technical Committee responsible for the interpretation of measurement The main drafters of this specification. Li Chunhui (China Institute of Metrology) Drafters participate. Xu Yinghua (China Institute of Metrology) Shen Wenxin (Zhejiang Institute of Metrology) Zhang Yuan (large national oil and gas flow metering stations Nanjing sub-station) Zhuang Tao (Liaoning Provincial Institute of Metrology) Yan Jiwei (Henan Institute of Metrology) Dingyue Chen (Dandong City-Bo Control Co., Ltd.)

1 Scope (1) 2. Referenced Documents (1) 3 Terms and Definitions (1) 4 Overview (2) 4.1 Composition (2) 4.2 works (2) 4.3 Purpose (2) 5 Metrological characteristics (2) 5.1 means the absolute pressure range (2) 5.2 means flow range (2) 5.3 nozzle discharge coefficient (3) 5.4 temperature measurement, pressure measurement instruments (3) Timer 5.5 (3) 5.6 humidity correction (3) 6 calibration conditions (3) Environmental conditions 6.1 (3) 6.2 Working medium conditions (3) 7 calibration items and calibration methods (3) 7.1 calibration items (3) 7.2 Calibration method (3) Expression 8 calibration results (4) 9 Recalibration interval (4) During the verification Appendix A (5) Appendix B humidity correction method (7) Appendix C Uncertainty assessment procedures (8) Appendix D positive pressure calibration device (10) Appendix E calibration certificate data sheet format (12) Critical flow Venturi nozzle Gas Flow Standards at

1 Scope

This instruction applies to school calibration of critical flow Venturi nozzle gas flow standard method (hereinafter referred to as the device) Verification and registration period.

2 Citations

GB/T 21188-2007/ISO 9300.2005 "with a critical flow Venturi nozzle Measurement of gas flow" JJG620-2008 "critical flow Venturi nozzle verification procedures" JJG643-2003 "standard table method flow standard device test procedures" JJF 1001-1998 "common measurement terms and definitions" JJF 1004-2004 "flow measurement terminology and definitions" JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement" When using this specification the calibration should be noted that using the currently valid version of the documents cited.

3 Terms and Definitions

3.1 Critical Flow Venturi nozzle criticalflowVenturinozzle For measuring the gas flow rate, inlet aperture is gradually reduced and then gradually expanded to the throat, the larynx can meet the local sound Speed measuring tube (hereinafter simply referred to as nozzles). 3.2 throat throat The inner diameter of the smallest section of the nozzle. 3.3 flow coefficient dischargecoefficient, Cd Stagnation under the same parameters, flow through the nozzle of the actual mass flow qm with a one-dimensional ideal gas, isentropic flow through nozzles The ratio of the mass flow over qmi, and its expression is Cd = qmqmi 3.4 throat Reynolds throatReynoldsnumber, Rent In nozzle throat diameter d as feature sizes, using a nozzle inlet conditions stagnation gas dynamic viscosity μ0 computing Reynolds number is calculated to give the Rent = 4qmπdμ0 3.5 Critical backpressure than criticalback-pressureratio, pcr When stagnation certain parameters, the maximum mass flow through the nozzle, the static pressure at the nozzle exit its upstream Maximum pressure ratio of stagnation. 3.6 decompressing means negativepressurefacility

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