I have a pressure sensor application, where I use Integrated pressure 
sensors that have: ground, +5VDC, and signal wires. The output signal is 
in the 0 - 5 VDC range. I have had several of these of 2 manufacturers 
fail, don't know the cause, but thinking ESD might be a factor. The 
sensors are Freescale MPX5700GP, and Measurement specialties 
MSP-300-100-P-3-N-1. Failures have been both in circuit, and no 
connected. The system has been in operation for 4 years with 3 failures.

Both varieties have a plastic weatherproof connector on the end of 2 
feet pigtail cable. The pins are recessed so accidentaly touching of the 
pins not likely, though a spark could jump the 1/16" recess. The 
Measurement Specialties unit comes with a covered 3 conductor cable. The 
Freescale unit is meant for board mounting. I solder wires to the 
terminals with heat shrink over the pin/solder and the 3 wires which 
then got to the connector as above. he sensor is then potted in a 
epoxy/milled fiberglass material with a 1/4" brass close nipple for 
pressure port and a hole at the ambient port (these are gauge not 
absolute pressure units).

There are the recommended capacitors on board with the PIC, I'm thinking 
more of protecting the loose sensor.

The usage is natural gas, 50 PDI. max., the gas has a water vapor near 
freezing, and the water in the well is salty.

I could easily add some discrete components like MOV, Diode, etc. to 
help the situation. What are suggestions.


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