It sounds like you are not quite sure as to whether the failures are 
caused by ESD or damage from incompatible media.

One type of solution that could make both cases better but is more 
complex would be to use a bubbler system.  This prevents contact with 
the media and can help to isolate the sensor electrically as well.

Basically, you hang a conduit (tygon tubing, or whatever) down into the 
location to be measured.  The top goes to a 'T' fitting that splits out 
to your pressure sensor and a pressure source.  The source can be any 
supply of air pressure that is slightly higher than your full scale 
pressure to be measured.  The air pressure line has a solenoid in it so 
you can turn it on to purge the line, shut it off, wait a bit then take 
a pressure measurement.  The air pressure in the tubing will bubble out 
the bottom (hence the name bubbler).  When it turns off the system will 
return to static pressure to be measured.

On 2/19/2010 1:55 PM, Carl Denk wrote:
> First it was the 2 Freescale sensors failed say a year apart, then
> thinking it was a particular model that was the problem, I bought 1
> Measurement specialties sensor as a trial, and after a near a year ago,
> and bought 2 more after a few months as spares. When one of the newer
> sensors failed, I began to question if there was another common issue
> causing the problem, and asked for help.
>
> One item I turned up as ordering some new Freescale sensors. Several
> years ago, there was only one (at least that's what I thought) model
> sensor of this type/pressure available. Now there are 2. There is a
> MPX5010G, newer MPX5010G1. The newer is commercial/industrial qualified,
> and comes WITH LDFRM (What ever that is, I couldn't find).
>
> As for the encapsulation, I had thought that as a possibility, adding
> considerable to the bonded mass of the original case, with thermal
> effects the concern. Protection from light physical damage, and moisture
> is main concern. The 3 wires are soldered (probably a no lead) to the
> terminals, carefully heat shrink individual wires (aircraft quality
> teflon), and then heat shrink over the 3 wires to the connector. I have
> opened the connector area, and no issues found there.
>
> One possibility is, the ambient pressure port, and pressure ports could
> not, both, be pointed downward to drain any liquid, and the application
> could have a little moisture exposure. For the new encapsulation, I plan
> to provide both ports in the same direction, and mount in a downward
> direction to minimize liquid intrusion. I had questioned what the
> preferred orientation of the Measurement Specialties sensor, never
> received an answer. I mounted it horizontal, to minimize damage to the
> cable which comes out the opposite end from the male threaded port. A
> 2nd issue, was I couldn't find an ambient port, and assumed the cable
> sheath provided the port. Again Specialty didn't respond.

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