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Barometer - Low Voltage Measurement


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#1 embayweather

embayweather
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  • 30 posts

Posted 03 July 2012 - 12:33 PM

I am building a weather station using Labjack and various components . I am nearing the end now, and one of the final projects is a barometer. I am using a MPXM2102A-ND sensor (data sheet http://datasheet.oct...heet-46224.pdf). In essence I can power from battery or from the onboard U3 supply. Both give miliivolt readings in the 20 - 40 mV area. I need to effectively measure these to do the pressure conversion. I am feeding the input from the sensor in via a LJTick amp, channel B. However, I cannot seem to get any increase in voltage out no matter where I ahem the dip switches for channel B. Measuring straightforward mV with a channel least to fluctuations as I need to measure to three decimal places . I had thought of putting a capacitor across the output to perhaps try and ease that, but an increase in voltage may well do the same. Measuring the output at the sensor itself with a multimeter when not connected to the U3 gives a completely steady signal when run on battery. I really would appreciate your help with this as I am so near the end.I should mention that I have a CB15 module in to which other sensors are plugged. Would the amplifier be better in that?

Thank you for your advice.

Best wishes

Mike

#2 LabJack Support

LabJack Support
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Posted 03 July 2012 - 01:24 PM

I started a page on bridge troubleshooting. See how this works for you:

http://labjack.com/s...et/appendix-d.1

The general idea is to use a DMM to see if the LJTIA has the correct input and output voltage, and use the test panel in LJControlPanel to see if the LabJack reading agrees with the DMM.


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