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 12: Electrical pulse devices/functions

Table of contents


1.0 Scope

This part of the Specifications applies to pulse generators/functions and associated pulse transmitting and receiving devices submitted for approval.

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 error

The MPE shall not exceed ± 0.05% at any point within the range for which approval is sought.

3.0 Marking requirements

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

3.1 Pulse generators

3.1.1 Non-integral pulse generators

3.1.1.1 Where a pulse generator is a separate entity which can be attached to an approved gas meter or ancillary device, the following information shall be marked on a nameplate attached to the pulse generator:

  1. Number of pulses per unit of measure or the measured quantity per pulse input;
    1. Where the information content of the pulse output may vary with the device on which the pulse generator is installed, a nameplate, tag, sticker, display or other suitable means for marking the required information shall be provided by the manufacturer.
  2. Maximum frequency of input;
  3. Type and amplitude of output signal or contact rating (e.g. "form C" or "form A").
3.1.2 Integral pulse generators/functions

3.1.2.1 Where a gas meter or an ancillary device incorporates a pulse generator/function, the following information shall be marked on a nameplate mounted on the host meter/device:

  1. The number of pulses corresponding to a unit of measured quantity or the number of measured units corresponding to one output pulse;
  2. Type and amplitude of output signal, or contact rating (e.g. "form C" or "form A");
  3. Departmental approval number of the meter/device with the pulse generator.

3.2 Relays and signal amplifiers

3.2.1 The following information shall be marked on a nameplate attached to the device:

  1. Type of input and output signals;
  2. Maximum voltage and frequency of input signal, and of output signal for amplifiers;
  3. Minimum input voltage;
  4. Connection diagram (does not need to be readily visible).

3.3 Pulse receivers

3.3.1 Non-integral pulse receivers shall be marked with the following information on a nameplate attached to them:

  1. Type of input signal;
  2. Minimum and maximum input voltage (as applicable);
  3. Frequency of input signal;
  4. The number of pulses corresponding to a unit of measured quantity or the number of measured units corresponding to one input pulse;
  5. Connection diagram (does not need to be readily visible).

3.3.2 Devices equipped with integral pulse receivers shall be marked with the information required in 3.3.1 on a nameplate attached to the device or made accessible through other means.

3.4 Automatic meter reading devices

Automatic meter reading (AMR) devices shall have the applicable information of this section marked on the nameplate or displayed where a display of the marking is permitted.

4.0 Performance tests

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

4.1 Evaluation tests

4.1.1 The following tests shall be done for the pulse input or output or both if applicable, at reference and "other than reference" environmental conditions:

  1. Tests at the maximum pulse rate specified by the manufacturer;
  2. Tests at the minimum level of input signal voltage to relays, amplifiers and pulse receivers.

4.1.2 The duration of all tests shall be a sufficient to ensure that the accumulated pulses can be determined with a resolution of at least 0.01%.

4.1.3 Where the signal is transmitted or received as a digital representation of an accumulated value, the requirements of 4.1.1 and 4.1.2 shall apply.

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