Sierra Instruments' QuadraTherm 640i / 780i Thermal Mass Flow Meter has 4 sensors
Sierra Instruments' QuadraTherm 640i / 780i Thermal Mass Flow Meter Series features sensor design advancements, coupled with a proprietary iTherm “brain.” The 780i inline version achieves gas mass flow rate measurement accuracy of ±0.5% of reading above 50% of the full scale (air).
At the heart of the 640i / 780i is its QuadraTherm sensor and proprietary iTherm algorithm set. QuadraTherm introduces four sensors — three precision platinum temperature sensors and one no-drift DrySense mass velocity sensor. The QuadraTherm sensor isolates forced convection (the critical variable for measuring gas mass flow rate) by calculating and then eliminating unwanted heat-transfer components, like sensor stem conduction.
With Dial-A-Pipe, customers can relocate the probe to different pipe sizes and types in the field. With Dial-A-Gas, iTherm provides gas change capability.
Sierra has developed an iTherm Gas Library which stores proprietary Gas Packets. A Gas Packet is analogous to the DNA of a specific gas. It stores all the parameters needed to instantly calculate the thermodynamic and transport properties of every gas or gas mixture versus temperature and pressure.
The QuadraTherm is available in two models: the 640i insertion and 780i inline. The QuadraTherm family has a no-drift sensor with lifetime warranty; has multivariable output: mass flow, temperature, pressure (optional); measures all inert and all non-condensing clean gases; flammable gases (methane, propane, hydrogen, and digester gas); repeatability for mass flow rate is ±0.15% ; ValidCal Diagnostics to validate calibration in the field; and gas accuracy is ±1°C (1.8°F).