1).ISO9001:2008, A grade. 2).non-contact mode--radio frequency technology 3).inflammable gas: natural gas, LPG,coal gas, etc Scope of applications: Apply to flow measurement of inflammable gas, such as natural gas, liquefied oil gas, coal gas and etc. Consumers can use gas by card, and one card, one gas meter. Air volumn in gas meter will be input, and valve of gas meter can automatically open ...