THERMAL FLOWMETER OF GAS CONSUMPTION OF ALTERNATE POWER Russian patent published in 2008 - IPC G01F1/68 

FIELD: invention refers to measuring technique namely to thermal flowmeters for measuring of gas consumption in diapason 0-100 mg/s.

SUBSTANCE: in body of arrangement there are heat exchanger of controlled power with heating spiral, gas distributing chamber, two measuring and two thermal compensating channels in which there are installed thermal sensitive elements in shape of identical temperature-sensitive resistors, additional spirals. Measuring and thermal compensating channels are hermetically connected with gas distributing chamber. Additional spirals are located on external surfaces of measuring and thermal compensating channels. Temperature sensitive resistors of thermal compensating channels and also in-series connected spiral of heat exchanger and additional spirals are switched to power control block. At that in quality of thermal sensitive elements they use temperature-sensitive resistors without indirect heating. Heating of temperature-sensitive resistors is executed directly by passing through them of current from source of feeding of unchangeable in time constant voltage. Block of converting output signal is fulfilled in shape of bridge network whose one arm is made up with in-series connected between them thermal-sensitive resistors in measuring channels.

EFFECT: increases sensitiveness of arrangement.

1 dwg