S-G-03–Specifications for the approval of type of gas meters, ancillary devices and associated measuring instruments

Category: Gas
Issue date:
Effective date:
Revision number: 1
Supersedes: LMB-EG-08 and S-G-03


Part 17: Temperature and pressure transmitters

Table of contents


1.0 Scope

This part of the Specifications applies to temperature and pressure transmitters submitted for approval.Footnote 17-1

2.0 Metrological requirements

The applicable requirements of Part 1, section 7.0 shall apply unless otherwise stated in this section.

2.1 Maximum permissible errors

The following MPEs shall apply at any point within the range for which approval is sought (see Part 17, Table 1).

Part 17, Table 1: Maximum permissible errors for transmitters
Transmitter type Test conditions Low pressure port MPE
Temperature Reference n/a ± 0.5 °C
"Other than reference" n/a ± 1 °C
Pressure (absolute and gauge) Reference n/a ± 0.5% of reading
"Other than reference" n/a ± 1% of reading
Differential Pressure Reference Atmosphere ± 0.5% of readingFootnote 17-2
± 1% of readingFootnote 17-3
75% of the maximum operating pressure ± 1% of readingFootnote 17-2
± 2% of readingFootnote 17-3
"Other than reference" Atmosphere ± 1% of readingFootnote 17-2
± 2% of readingFootnote 17-3

3.0 Marking requirements

In addition to the applicable requirements of Part 1, section 9.0, the following shall apply.

3.1 Differential pressure transmitters

The pressure connection ports shall be marked to distinguish the low pressure port from the high pressure port.

4.0 Performance tests

The applicable requirements of Part 1, section 12.0 shall apply unless otherwise stated in this section.

4.1 Test conditions

4.1.1 Temperature transducers
4.1.1.1 Working temperatures (tw) at reference environmental conditions

The flowing gas temperature sensing element shall be held at the minimum temperature marked on the nameplate, at 25%, 50% and 75% of the span and at the maximum temperature marked on the nameplate.

4.1.1.2 Working temperatures (tw) at "other than reference" environmental conditions

The flowing gas temperature sensing element shall be held at 25% and 75% of the span.

4.1.2 Pressure transducers
4.1.2.1 Working pressures (pw)

The flowing gas pressure shall be held at 25%, 50%, 75% and 100% of the pressure range, first with increasing pressure and then with decreasing pressure, ensuring that in reaching any test point, the change in pressure is in one direction only.

4.1.3 Differential pressure transducers
4.1.3.1 Operating conditions
  1. Differential pressure transducers shall be tested at 10%, 25%, 50%, 75% and 100% of calibrated differential pressure range with the low pressure port open to atmosphere, first with increasing pressure and then with decreasing pressure.
  2. At reference environmental conditions, differential pressures according to 4.1.3.1(a) shall be repeated with static pressure equivalent to 75% of the maximum operating pressure applied to the low pressure port.

4.2 Evaluation tests

4.2.1 Accuracy testing
4.2.1.1 Temperature transducers

At reference and "other than reference" conditions, tests shall be performed with the flowing gas temperature sensing element held at temperatures as stated in subsection 4.1.1 (see Part 17, Table 2).

Part 17, Table 2: Temperature transducers — accuracy testing
Environmental conditions Working temperature (tw) (% of span and Tmin or Tmax marked on the nameplate)
Reference Tmin, 25%, 50%, 75%, Tmax
"Other than reference" (low ambient temperature) 25%
"Other than reference" (high ambient temperature) 75%
4.2.1.2 Pressure transducers

At reference and "other than reference" conditions, tests shall be performed at working pressures as stated in subsection 4.1.2.1 (see Part 17, Table 3).

Part 17, Table 3: Pressure transducers — accuracy testing
Environmental conditions Working pressure (pw) (% of range)
Reference 25%, 50%, 75%, 100%, 75%, 50%, 25%
"Other than reference"
4.2.1.3 Differential pressure transducers

At reference and "other than reference" conditions, tests shall be performed at operating conditions as stated in subsection 4.1.3.1 (see Part 17, Table 4).

Part 17, Table 4: Differential pressure transducers — accuracy testing
Environmental conditions Differential pressure (% of range) Pressure at the low pressure port
Reference 10%, 25%, 50%, 75%, 100%, 75%, 50%, 25%, 10% Atmosphere
75% of the maximum operating pressure
"Other than reference" 10%, 25%, 50%, 75%, 100%, 75%, 50%, 25%, 10% Atmosphere

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