Tracked Changes. Gas meters. Diaphragm gas meters|Battery-powered devices, Accuracy, Certificates of conformity, Temperature, Instrument cases, Vibration, Testing conditions, Screwed fittings, Errors, Pressure, Impact testing, Ageing tests, Flowmeters, Strength of materials, Drop tests, Vibration testing, Gas-supply meters, Performance testing, Electrical resistance, Chemical-resistance tests, Electromagnetic compatibility, Leak tests, Adhesion tests, Environmental testing, Diaphragms (mechanical components), Working range, Volume flowmeters, Flow rates, Marking, Corrosion resistance, Bend testing, Mechanical testing, Test equipment, Pipe connections, Corrosion tests, Durability, Display devices, Dimensions, Endurance testing, Torque, Flanges, Water-vapour tests, Protective coatings, Stability, Electronically-operated devices