Method for operating a capacitive pressure measurement cell, and a capacitive pressure measurement device
AssigneeIfm Electronic GmbH
InventorsHeinz WALTER, Manfred MAURUS, Peter KIMBEL, Alexander OPPE
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Abstract
The disclosure relates to a method for operating a capacitive pressure measurement device. In order to achieve an insensitivity to external signal sources, the disclosure proposes continuously varying the working frequency of the pressure measurement device so that a resonance formation with externally injected (interfering) frequencies is avoided.
Claims9
A method for operating a capacitive pressure measuring device, wherein the pressure measuring device comprises a pressure measuring cell comprising a measuring capacitor and a reference capacitor, which are applied with an internal excitation voltage in the form of an alternating square wave signal, and wherein the pressure measuring value p is obtained from the capacitance values of the measuring capacitor and the reference capacitor,
- wherein the excitation voltage is converted by means of the measuring capacitor by integration into an intermediate signal, and wherein the intermediate signal is fed to a comparator oscillator, as a result of which finally the excitation voltage is generated,
- wherein
- at least one threshold value of the comparator oscillator is changed, so that the excitation voltage has a varying frequency.
Dependencies are inferred from the claim text.