CEN/TC 237/WG 4 - Associated conversion devices

This document specifies the requirements and tests for the construction, performance, safety and conformity of gas-volume electronic conversion devices associated to gas meters, used to measure volumes of fuel gases of the 1st and 2nd families according to EN 437.
This document is intended for type testing, the detailed relevant provisions of which are given in Annex A.
Only three kinds of conversion are treated in this document:
-   conversion as a function of temperature only (called T conversion);
-   conversion as a function of the pressure and of the temperature with constant compression factor (called PT conversion);
-   conversion as a function of the pressure, the temperature and taking into account the compression factor (called PTZ conversion).
This document is not relevant to temperature conversion integrated into gas meters which only indicate the converted volume.
Gas-volume conversion devices consist of a calculator and a temperature transducer or a calculator, a temperature transducer and a pressure transducer locally installed.
For application of this document, a conversion device may be, as a choice of the manufacturer, considered as a complete instrument (Type 1) or made of separate elements (Type 2), according to the definitions given in 3.1.20.1 and 3.1.20.2.
In this last case, the provisions concerning pressure transducers, temperature sensors and temperature transducers are given in Annexes B, C and D respectively.
Any conversion device can provide an error curve correction for a gas meter.
NOTE   When rendering an account to an end user the readings from the conversion device can be used in conjunction with the readings from a gas meter conforming to EN 1359, EN 12480, or EN 12261, as appropriate, or to any other appropriate and relevant international or national standard for gas meters, without prejudice of national regulations.

Part 3 of this European Standard specifies the requirements and tests for the construction, performance, safety and conformity of flow computers (FCs) used to meet the metrological and technical requirements of a high accuracy volume conversion device.
They are used to determine volume of fuel gases, including those of the first and second families according to EN 437.
For the purpose of this European Standard, only flow computers that are intended to operate with ultrasonic meters according to ISO 17089 1 or gas turbine meters conforming to EN 12261 are considered.
For the purpose of this European Standard only classification classes E2 and M1 are considered for the flow computer calculator.
FCs are equipped with external separate transducers for pressure and temperature which may be approved separately.
The provisions concerning pressure and temperature transducers are given in Annex B and C.
Requirements and tests are given for energy calculator in EN 12405 2.

This European Standard specifies the requirements and tests for the construction, performance, safety and conformity of conversion devices used to determine the energy of fuel gases described in the Table 1, including those of the 1st and 2nd families according to EN 437.
The energy conversion device (ECD) considered in this standard consists of an energy calculator (EC) and is associated with the following devices and/or functions:
-   a volume conversion device (VCD) or a flow computer used as gas meter conversion, either conforming to EN 12405-1, or to prEN 12405-3, for high accuracy measurements;
-   a calorific value determination device (CVDD).
Requirements for type approval tests of the devices, not included in the above-mentioned standards are described in appropriate annexes specified in Table 6.
For the purpose of this European Standard, the term "volume conversion devices" (VCDs) includes flow computers (FCs).
A single calculator may undertake the volume conversion functions for different metering lines.

To revise the Annex ZA, and the associated body text only, of EN 12405-1 to ensure the alignment with the Directive 2014/32/EU.

This European Standard specifies the requirements and tests for the construction, performance, safety and conformity of gas volume electronic conversion devices associated to gas meters, used to measure volumes of fuel gases of the 1st and 2nd families according to EN 437.
This European Standard is intended for type testing, the detailed relevant provisions of which are given in Annex A.
Only three kinds of conversion are treated in this European Standard:
   conversion as a function of temperature only (called T conversion);
   conversion as a function of the pressure and of the temperature with constant compression factor (called PT conversion);
   conversion as a function of the pressure, the temperature and taking into account the compression factor (called PTZ conversion).
!This document is not relevant to temperature conversion integrated into gas meters which only indicate the converted volume."
EN 12405-2 for energy conversion is in preparation.
Gas-volume conversion devices consist of a calculator and a temperature transducer or a calculator, a temperature transducer and a pressure transducer locally installed.
For application of this European Standard, a conversion device may be, as a choice of the manufacturer, considered as a complete instrument (Type 1) or made of separate elements (Type 2), according to the definitions given in 3.1.18.1 and 3.1.18.2.
In this last case, the provisions concerning pressure transducers, temperature sensors and temperature transducers are given in Annexes B, C and D respectively.
Any conversion device can provide an error curve correction for a gas meter.
NOTE   When rendering an account to an end user the readings from the conversion device can be used in conjunction with the readings from a gas meter conforming to EN 1359, EN 12480, or EN 12261, as appropriate, or to any other appropriate and relevant international or national standard for gas meters, without prejudice of national regulations.

After third paragraph insert:This document is not relevant to temperature conversion integrated into gas meters which only indicate the converted volume.

This European Standard specifies the requirements and tests for the construction, performance, safety and conformity of gas volume electronic conversion devices associated to gas meters, used to measure volumes of fuel gases of the 1st and 2nd families according to EN 437.
This European Standard is intended for type testing, the detailed relevant provisions of which are given in Annex A.
Only three kinds of conversion are treated in this European Standard:
-   conversion as a function of temperature only (called T conversion);
-   conversion as a function of the pressure and of the temperature with constant compression factor (called PT conversion);
-   conversion as a function of the pressure, the temperature and taking into account the compression factor (called PTZ conversion).
EN 12405-2 for energy conversion is in preparation.
Gas-volume conversion devices consist of a calculator and a temperature transducer or a calculator, a temperature transducer and a pressure transducer locally installed.
For application of this European Standard, a conversion device may be, as a choice of the manufacturer, considered as a complete instrument (Type 1) or made of separate elements (Type 2), according to the definitions given in 3.1.18.1 and 3.1.18.2.
In this last case, the provisions concerning pressure transducers, temperature sensors and temperature transducers are given in Annexes B, C and D respectively.
Any conversion device can provide an error curve correction for a gas meter.
NOTE   When rendering an account to an end user the readings from the conversion device can be used in conjunction with the readings from a gas meter conforming to EN 1359, EN 12480, or EN 12261, as appropriate, or to any other appropriate and relevant international or national standard for gas meters, without prejudice of national regulations.

This European Standard specifies the requirements and tests for the construction, performance, safety and conformity of gas-volume electronic conversion devices associated to gas meters, used to measure volumes of fuel gases of the 1st and 2nd families according to EN 437.
Only three kinds of conversion are treated in this standard:
- conversion as a function of temperature only (called T conversion);
- conversion as a function of the pressure and of the temperature with constant compressibility factor (called PT conversion);
- conversion as a function of the pressure, the temperature and taking into account the compressibility factor (called PTZ conversion).
These gas-volume conversion devices consist of a calculator and a temperature transducer or a calculator, a temperature transducer and a pressure transducer locally installed.
Any conversion device can provide an error curve correction for a gas meter.
NOTE   When rendering an account to an end user the readings from the conversion device can be used in conjunction with the readings from a gas meter conforming to EN 1359, prEN 12480, or prEN 12261, as appropriate, or to any other appropriate and relevant international or national standard for gas meters, without prejudice of national regulations.
This standard is intended for type testing only.
Annex A is normative and annex B is informative.