High reliability pressure sensor

A method for measuring a pressure comprising:

• (a) providing a pressure sensor having first and second sensor elements, the first and second sensor elements connected to corresponding first and second signal conditioning circuits, the first signal conditioning circuit having a first gain and the second signal conditioning circuit having a second gain that is a fraction of the gain of the first signal conditioning circuit;
• (b) comparing the output of the first signal conditioning circuit to a first threshold and, upon the output of the first signal conditioning circuit being less than or equal to the first threshold, setting an error flag;
• (c) upon the output of the first signal conditioning circuit exceeding the first threshold, comparing the output of the second signal conditioning circuit to the first threshold and upon the output of the second signal conditioning circuit being less than or equal to the first threshold, setting an error flag;
• (d) upon the output of the second signal conditioning circuit exceeding the first threshold, comparing the output of the first signal conditioning circuit to a second threshold;
• and
• (e) upon the output of the first signal conditioning circuit exceeding the second threshold, comparing the output of the second signal conditioning circuit to a third threshold and, upon the output of the second signal conditioning circuit exceeding the third threshold, setting an error flag.

A method for measuring a pressure comprising:

• (a) providing a pressure sensor having first and second sensor elements;
• (b) determining an absolute value of the difference of the outputs of the first and second sensor elements;
• (c) comparing the absolute value of the difference of the outputs of the first and second sensor elements to a maximum difference factor;
• and
• (d) upon the absolute value of the difference of the outputs of the first and second sensor elements greater than the maximum difference factor, setting an error flag.

A pressure sensor assembly for a hydraulic system comprising:

• a pressure sensor housing adapted to be mounted upon a hydraulic system;
• a pressure sensor diaphragm carried by said pressure sensor housing;
• a first pressure sensing element mounted upon said pressure sensor diaphragm;
• a second pressure sensing element mounted upon said pressure sensor diaphragm;
• a first signal conditioning circuit connected to said first pressure sensing element, said first signal conditioning circuit having a first gain and being operable to generate a first pressure signal at a first output port;
• a second signal conditioning circuit connected to said second pressure sensing element, said second signal conditioning circuit having a second gain that is a fraction of said first signal conditioning gain, said second signal conditioning circuit being operable to generate a second pressure signal at a second output port;
• and
• an electronic device connected to said output ports of said first and second signal conditioning circuits, said electronic device being operative to compare said first pressure signal to a first threshold and said second pressure signal to a second threshold, said electronic device being further operative, upon both pressure signals exceeding both thresholds, to generate an error signal.

A pressure sensor assembly for a hydraulic system comprising:

• a pressure sensor housing adapted to be mounted upon a hydraulic system;
• a pressure sensor diaphragm carried by said pressure sensor housing;
• a first pressure sensing element mounted upon said pressure sensor diaphragm;
• a second pressure sensing element mounted upon said pressure sensor diaphragm;
• a first signal conditioning circuit connected to said first pressure sensing element, said first signal conditioning circuit having a first gain and being operable to generate a first pressure signal at a first output port;
• a second signal conditioning circuit connected to said second pressure sensing element, said second signal conditioning circuit having a second gain that is a fraction of said first signal conditioning gain, said second signal conditioning circuit being operable to generate a second pressure signal at a second output port;
• and
• an electronic device connected to said output ports of said first and second signal conditioning circuits, said electronic device being operative to compare said first and second pressure signals to a first threshold and, upon either of said first and second pressure signals being less than said first threshold, generating an error signal;
• said electronic device being further operable to compare said first pressure signal to a second threshold and said second pressure signal to a third threshold and, upon said first pressure signal exceeding said second threshold and said second pressure signal exceeding said third threshold, generating an error signal.

A pressure sensor assembly for a hydraulic system comprising:

• a pressure sensor housing adapted to be mounted upon a hydraulic system;
• a pressure sensor diaphragm carried by said pressure sensor housing;
• a first pressure sensing element mounted upon said pressure sensor diaphragm;
• a second pressure sensing element mounted upon said pressure sensor diaphragm;
• a first signal conditioning circuit connected to said first pressure sensing element, said first signal conditioning circuit having a first gain and being operable to generate a first pressure signal at a first output port;
• a second signal conditioning circuit connected to said pressure sensing element, said second signal conditioning circuit having a second gain that is a fraction of said first signal conditioning gain, said second signal conditioning circuit being operable to generate a second pressure signal at a second output port;
• and
• an electronic device connected to said output ports of said first and second signal conditioning circuits, said electronic device being operative to compare said first and second pressure signals to a first threshold and, upon either of said first and second pressure signals being less than said first threshold, generating an error signal, said electronic device being further operable to determine an absolute value of the difference between said first pressure signal and said second pressure signal and further wherein said electronic controller is also operable to compare said difference to an error value and, upon said difference exceeding said error value, to generate an error signal.