ГЭТ 49-2016 (НИО 231)

Standard name:

ГЭТ 49-2016 State primary special standard of pressure indicator for the absolute pressure range in the circuit 1·10[^-6] ÷ 1·10[^3] Pa

Type of measurement:

Pressure measurements, vacuum measurements

Structural division: name НИО\НИЛ:

Research Department of State Standards in the Field of Pressure Measurements

Guardian Scientist:

Chernyshenko Alexander Alexandrovich, PhD

Year of creation:

1980

Year of re-confirmation:

2021

Operating principle:

The standard's operating principle is based on the change in capacitance of a capacitor formed by an elastic sensing element (membrane) and a measuring (compensating) electrode isolated from it, under the influence of the measured pressure. This change in capacitance is converted into an electrical signal.The standard is based on the membrane-capacitance measurement method using the method of compensating for membrane deflection by electrostatic action. The capacitive method of fixing the membrane's position involves converting its mechanical movements into an equivalent change in the electrical capacitance of a measuring capacitor located in the transducer's measuring chamber. This change in capacitance is automatically compensated for by an electrical action that returns the membrane to its original position. A vacuum-reducing unit is used for measurements from 1 x 10^-6 to 1 x 10² Pa. Its operating principle is based on a pressure reduction method, which transfers the unit of pressure from the low and medium vacuum region to the high vacuum region. The vacuum-reducing unit utilizes a system consisting of three vacuum chambers connected in series through which a rarefied gas flows. Diaphragms of high and low conductivity are installed between the chambers.

Composition of the standard:

Reference system based on membrane-capacitance compensating transducers (MEPC), reproducible pressure range of 1 10[^-2]– 1 10[^3]Pa;

Reference system based on membrane-capacitance vacuum gauges, reproducible pressure range of 1 10[^-3]– 1 10[^3]Pa;

Reference system based on a vacuum-reducing unit (VREU), reproducible pressure range of 1 10[^-6]– 1 10[^-2]Pa;

Specialized equipment for creating and maintaining pressure

Main metrological characteristics

Estimation of random error in the reproduction of units
(name of quantity, value, unit of measurement – parameters)

no more than:

0.15 x 10^-2 in the range of 1 x 10^-3 – 40 Pa;
0.30 x 10^-2 in the range of 1 – 1 x 10³ Pa;
2.0 x 10^-2 in the range of 1 x 10^-6 – 1 x 10^-2 Pa.

Estimation of unremoved systematic error of reproduction
(name of quantity, value, unit of measurement – parameters)

no more than:

0.17 x 10^-2 in the range 1 x 10^-3 – 40 Pa;
0.30 x 10^-2 in the range 1 – 1 x 10³ Pa;
2.5 x 10^-2 in the range 1 x 10^-6 – 1 x 10^-2 Pa.

Standard uncertainty

– evaluated by type A:
(name of quantity, value, unit of measurement – parameters)

relative units

0.15 x 10^-2 in the range 1 x 10^-3 – 40 Pa;
0.30 x 10^-2 in the range 1 – 1 x 10³ Pa;
2.0 x 10^-2 in the range 1 x 10^-6 – 1 x 10^-2 Pa.

– assessed by type B:
(name of quantity, value, unit of measurement – parameters)

relative units

0.10 x 10^-2 in the range 1 x 10^-3 – 40 Pa;
0.30 x 10^-2 in the range 1 – 1 x 10³ Pa;
1.4 x 10^-2 in the range 1 x 10^-6 – 1 x 10^-2 Pa.

Total standard uncertainty
(name of quantity, value, unit of measurement – parameters)

0.18 x 10^-2 in the range 1 x 10^-3 – 40 Pa;
0.35 x 10^-2 in the range 1 – 1 x 10³ Pa;
2.4 x 10^-2 in the range 1 x 10^-6 – 1 x 10^-2 Pa.

Expanded uncertainty with coverage factor k = 2:
(name of quantity, value, unit of measurement – parameters)

0.36 x 10^-2 in the range 1 x 10^-3 – 40 Pa;
0.70 x 10^-2 in the range 1 – 1 x 10³ Pa;
4.8 x 10^-2 in the range 1 x 10^-6 – 1 x 10^-2 Pa.

Verification diagram:

Heads the state verification scheme for absolute pressure (vacuum) measuring instruments in the range of 10[^-8]- 10[^5]Pa.

Scope of application:

Instrumentation and precision engineering;
Vacuum technologies, electronics, space, and defense technologies;
Shipbuilding, aircraft and rocket engineering, nuclear energy, etc.;
Operational safety of technical facilities created in high-tech branches of science and engineering;

Results of applying the standard:

Metrological service (codes of calibration and measurement capabilities according to the CIPM classification): M.3.1.1.
International comparisons (KCDB comparison code list): 1997-1999 COOMET 154/RU/97 Slovakia 2004-2007; COOMET 295/RU/03 Slovakia 2009-2012; CCM.P-K12 USA, France, Japan, etc. (10 countries) 2016-2017; COOMET 711/TR/16 Turkey.
Development, production and implementation into metrological practice of vacuum measuring units and measuring instruments that implement the measurement principles embodied in the standard.
The standard ensures: the safe operation of technical facilities created in high-tech priority sectors of science and technology; the development of new diagnostic methods for structural materials, such as hydrogen diagnostics of materials and the analysis of impurity content of various gases in materials and products; the creation, as part of the import substitution program, of new, modern, domestic digital vacuum measurement instruments with an expanded measurement range; the integration of the Russian Federation into the global economy, expanding Russia's measurement capabilities in the field of pressure measurement; and the increased competitiveness of products manufactured by Russian industry in the global market.

The total number of measuring instruments traceable to ГЭТ 49-2016:

Hundreds of thousands

Ensuring the uniformity of measurements, participation in the CIPM MRA program:

2

PHOTO:

Information in the Federal State Information System "ARSHIN"