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Strain-Guage based Pressure Sensor

I just finished building a self-contained pressure sensing device using a MEMS strain-guage type sensor from Measurement Specialties. Single phase AC goes in one side, and a 0.5V-4.5V signal proportional to pressure input comes out the other side. The sensor has a rated max of 5″ of water.

The circuit is simple enough, the AC goes through a fuse and into a AC-DC converter. The output is regulated by a 5V regulator, which powers an op-amp and the sensor. The op-amp buffers the output of the sensor. I used a MAX4242 op-amp, as it can run on less than 5V, and has rail to rail inputs and outputs. This keeps my signal in the CMR range.
I have used products from Measurement Specialties in the past, and they seem to be very good products for the money. I have some of their button load cells which were very affordable and also have about twice the output signal (mV/V) of similar load cells from Omega or Futek.

Tags: MEMS, Pressure