公开(公告)号：US20210215519A1

公开(公告)日：2021-07-15

申请号：US17147863

申请日：2021-01-13

Applicant: Axetris AG

Inventor： Paolo Antonio Losio ,  Rolf Gebhardt

IPC: G01F1/696 ,  G01F1/69

Abstract: A gas flow measuring circuit includes at least one reference resistor and at least one variable resistor that varies in accordance with the characteristics of the flow of a gas and means for determination of the difference between the reference resistor and variable resistor, with at least one current loop arrangement including first current source means coupled in series with said reference resistor and second current source means coupled in series with said variable resistor wherein both resistors are connected to ground for providing an ideally constant current through the respective resistor to produce first voltages across the reference resistor and second voltages across the variable resistor, and voltage measuring means for measuring the voltage difference between said reference resistor and said variable resistor to produce a characteristic voltage difference representative of the characteristics of the gas.

公开(公告)号：US11448539B2

公开(公告)日：2022-09-20

申请号：US17147863

申请日：2021-01-13

Applicant: Axetris AG

Inventor： Paolo Antonio Losio ,  Rolf Gebhardt

IPC: G01F1/696 ,  G01F1/69

Abstract: A gas flow measuring circuit includes at least one reference resistor and at least one variable resistor that varies in accordance with the characteristics of the flow of a gas and means for determination of the difference between the reference resistor and variable resistor, with at least one current loop arrangement including first current source means coupled in series with said reference resistor and second current source means coupled in series with said variable resistor wherein both resistors are connected to ground for providing an ideally constant current through the respective resistor to produce first voltages across the reference resistor and second voltages across the variable resistor, and voltage measuring means for measuring the voltage difference between said reference resistor and said variable resistor to produce a characteristic voltage difference representative of the characteristics of the gas.