QuadraTherm 640i/780i flow meters are the industry’s most precise thermal mass flow meters with an accuracy of +/- 0.5% of reading above 50% of full scale. Offered in both an insertion and inline versions, the QuadraTherm is ideal for precision gas flow measurement of natural gas, as well as other gases such as hydrogen, CO2 nitrogen and propane. Now with on board qMix gas mixing software, for the first time with thermal technology, customers can create and upload new gases as the gas composition changes-all without sending the meter back to the factory for recalibration. Buy online for next day shipping!