In view of the increasing diversification of sources of natural gas supply, consumers are increasingly being supplied natural gas with varying gas properties and thus with different combustion behavior. Accurate energy billing - especially for large customers - requires continuous measurement of the heating value. If the consumer has thermally sensitive processes or burners, the properties of the supplied gas must be monitored and, if necessary, corrected to the required value through conditioning.

To cope with varying gas properties when supplying heat to processes, a suitable gas measuring technology is needed, such as the comprehensive CWD instrument series (Calorimetry, Wobbe index, specific Density) offered by Union Instruments. With this, calorimetric values such as the heating value and the Wobbe index of natural gas, biogas, biomethane, process gases, and the like can be determined according to the DVGW (German Technical and Scientific Association for Gas and Water) worksheets G 260 and G262.

This includes direct measuring of the Wobbe index through the energy produced when a defined gas flow is combusted. Unknown or unexpected components in the gas are also detected and taken into consideration in the measurement. This is of utmost importance in the case of rapidly changing gas composition of, for example, residual gases from chemical processes or substitute gases in the steel industry.

The CWD2005 CT calorimeter is approved as a calorific value measuring instrument for custody transfer. For use in hazardous areas, the CWD2005 DP version is available.