JJG 1073-2011Verification Regulation of Pressure Type SF6 Gas Density Monitors (English PDF)

1 Scope

This Regulation is applicable to the initial verification, subsequent verification and examination in service of pressure type SF6 gas density monitors or gas density relay (hereinafter referred to as instrument) with measuring range of (-0.1~0.9) Mpa, the bourdon tube as measuring element, with temperature compensating device and contact output function.

2 Normative References

This Regulation quotes the following documents.

JJG 52-1999 Verification Regulation of Bourdon Tube Pressure Gauge Pressure -

Vacuum Gauge and Vacuum Gauge for General Use

GB/T 22065-2008 Pressure Type SF6 Gas Density Monitors

For dated references, only the edition cited applies; for undated references, the latest edition of the reference document (including any amendments) applies.

3 Terms and Definitions

4 General

The instrument monitors SF6 gas density through the measurement of the SF6 gas pressure in the airtight equipment.

The working principle and basic structure of the instrument is to add temperature compensation function based on electric contact pressure gauge. The working principle is as follows. that elastic deformation occurs to the internal spring under the pressure, so terminal movement is caused, amplified through driving mechanism and transferred to indication device after temperature compensation, and finally the measured pressure value is indicated on the index plate through the pointer. Where the pressure drop to the alarm pressure or atresia pressure, the instrument gives alarm or atresia signal through connecting and

deltat=|t2-t1|,°C;

t2- the ambient temperature with the arbitrary value within -20°C~60°C, °C;

t1=20°C;

K1- the temperature compensation coefficient (0.02 %/°C).

5.9.2 Where the ambient temperature is less than -20°C,

delta2=±(delta-20+K2deltat) (2)

Where,

delta2 - the permissible value of temperature compensation error with ambient temperature less than -20°C (calculated according to the percentage of measuring range);

delta-20 - the permissible value of temperature compensation error with ambient temperature being -20°C (calculated according to the percentage of measuring range);

deltat=|t2-t1|,°C;

t2 - the ambient temperature with the arbitrary value less than -20°C, °C;

t1=-20°C;

K2- the temperature compensation coefficient (0.05% /°C).

6 General Technical Requirements