1. Gas Volume Electronic Conversion Devices,1996
2. Calculation of Compressibility Factor — part 1: Introduction and Guidelines;ISO/DIS 12213,1994
3. General Provision for Gas Volume Meters;OIML R6,1976
4. Diaphragm Gas Meter;OIML R31,1989
5. Compteurs de Volume de Gaz à Pistons Rotatifs and à Turbine;OIML R32,1973