Can you ellaborate on "3 failures". What exactly did fail? A wrong read value? PIC reset? etc 2010/2/17 Carl Denk > 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. > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- Ariel Rocholl Madrid, Spain -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist