boost pressure sensor

I have a boost pressure sensor that reads from 0psi to 36psi
it accepts 5V as power and outputs a siganl from .2 to 4.9volts (so 0psi will read .2 and 36psi will read 4.9volts)

but the datalogger I have was desinged to be used with a sensor that reads up to 50psi.
the original 50psi sensor also used 5v power but the output signal was 0 PSI making 0.5V and 50 PSI making 4.5Volts

so the problem is that the datalogger gets a much higher reading now.

I was thinking of using a Potentiometer/pot trimmer or resistor to reduce the voltage the datalogger sees

Figured I'd use Potentiometer/pot trimmer since I can fine tune it a bit over a set resistor.


Problem is most faq's I'v found on Potentiometer/pot trimmers talk about amps and are rated as Ohms
like 5ohm, 10ohm, 10k ohm etc......

any idea which one will work for me?
thanks

I think this is going to be a lot more complicated then just adding a resistor (or two).  You have two completely different ranges, on compeltely different scales. 

The MAP you have now reads 36psi over a 4.7vdc range (7.65psi/volt).  Your original one reads 50psi over a 4vdc range (12.5psi/volt) 

Basically, you will need to set up a circuit to read in the voltage of the current MAP and scale it to the output of the old MAP.  If you can come up with a linear relationship you should be able to do the conversion with an op amp, if it isn't linear (it should be) you can use a microcontroller to do the scaling for you.

Of course, the easiest thing to do would be get the right MAP sensor and not even mess with the scaling.  Check out www.newark.com , they have a ton of different pressure transducers, in a wide variety of ranges.

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Kevin Pierson

thanks