JJF 1240-2010_English: PDF (JJF1240-2010)
| Standard ID | USD | BUY PDF | Lead-Days | Standard Title (Description) | Status |
| JJF 1240-2010 | 399 |
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Calibration Specification for Gas Flow Calibration Facility by Means of Critical Flow Venturi Nozzles
| Valid |
| JJF 1240-1990 | 199 |
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O.T.N of the Primary Standard for the 1×1000N Force Standard Machine
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| 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 | 17,111 | | 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 | | Issuing agency(ies) | State 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
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.)
table of Contents
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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