Gas volume converters

Gas volume converters are electronic instruments associated with gas volume meters whose function is to provide correct information about the quantity of gas passed through the meter.

It is in fact known, due to the peculiar thermodynamic characteristics, that the volume of a gas is affected by environmental pressure and temperature conditions. For this reason, the quantities indicated by the meters under the various operating conditions do not offer an absolute guarantee of legality and must be traced back and switched to the corresponding quantities measured in defined standard pressure and temperature conditions (temperature of 15 °C and pressure of 1.01325 bar ) and, as such, usable for commercial purposes.

The gas volume conversion devices at basic conditions can be of 2 types, type 1 and type 2 .

In type 1 the pressure and temperature sensors are integral parts of the converter and the periodic verification is valid for 4 years.

The periodicity of the verification is 4 years and starts from the date of their commissioning, if the commissioning took place no later than two years from 31 December of the year of the supplementary metrological marking.

If the instrument was put into service more than two years after 31 December of the year indicated by the supplementary metrological marking, the first periodic check must be carried out by 31 December of the year indicated by the supplementary metrological marking increased by 6.

Subsequently, the check is carried out every 4 years from the date of the last check or, if necessary, after having carried out a repair which involved the removal of the instrument's seals.

In type 2 the pressure and temperature sensors are replaceable and the validity of the periodic check is 2 years

The periodicity of the verification is 2 years and starts from the date of their commissioning, if the commissioning took place no later than two years from 31 December of the year of the supplementary metrological marking.

If the instrument was put into service more than two years after 31 December of the year indicated by the supplementary metrological marking, the first periodic check must be carried out by 31 December of the year indicated by the supplementary metrological marking increased by 4.

Subsequently, the check is carried out every 2 years from the date of the last check or, if necessary, after having carried out a repair which involved the removal of the instrument's seals.

For instruments already subjected to periodic checks, the frequency of checks continues to be calculated starting from the last check carried out.

The owner of the measuring instrument requests the periodic verification at least five working days before the expiry of the previous verification or, in the case in which he has proceeded to have the instrument repaired, within ten working days starting from the date of the repair.

To check that the instruments used in legal measurement functions are regularly subjected to periodic verification and that the obligations required by Ministerial Decree 93/2017 are respected, the Chamber of Commerce periodically carries out random checks both on a sample of instruments already verified by the laboratories authorized for verification periodically and on the instruments in service with the owners of the instruments.

The owners of measuring instruments are subject to obligations relating to the correct maintenance of the instrument and the associated documentation and must communicate to the Chamber of Commerce of the district in which the instrument is in service the date of start of use and the end of use. use, in addition to the other elements indicated by Ministerial Decree 93/2017, under penalty of the application of the corresponding administrative sanctions.