Foil manometer
AssigneeMax-Planck-Gesellschaft Zur FöRderung Der Wissenschaften E. V.
InventorsFriedrich Mast, Gerold Schramm, Martin Münch
Life of this patent
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Abstract
A pressure gauge device that is operated as a thermal conduction manometer contains a measuring resistor (131) that is arranged in layer form on a self-supporting carrier foil and is in defined thermal contact with a gas whose pressure is to be measured. The thermal contact with the gas is through the carrier foil (11), a thermal conducting layer (123) and optionally through an extra absorber layer (124). The resistance, dependent on gas pressure, of the measuring resistor (131) is detected by a bridge circuit in which each measuring resistor (131) is assigned a reference resistor (136) whose resistance itself is dependent on or independent of pressure.
Claims20
A thermal conduction manometer comprising:
- a carrier foil;
- at least one electrically heatable measuring resistor arranged as a layer on a surface of the carrier foil;
- an isolating layer arranged on said measuring resistor;
- a thermal contact layer arranged on an opposed surface of said carrier foil, the thermal contact layer containing a recess having an opening through which a medium to be measured can flow into the recess;
- an absorber layer arranged in the recess and in contact with the thermal contact layer;
- a heating resistor arranged on the isolating layer for heating said measuring resistor, the heating resistor being adapted to at least partially compensate for heat passing from the measuring resistor to the medium to be measured, and
- at least one reference resistor spaced from and electrically connected to the measuring resistor to form part of a Wheatstone bridge,
- wherein heat generated by the measuring resistor passes substantially perpendicularly from the measuring resistor to the medium through the carrier foil, the thermal contact layer and the absorber layer, and
- pressure is determined as a function of heat passing to the medium.
Dependencies are inferred from the claim text.