Pre-Amplifying low voltages with PicoLog1216

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reindyr
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Joined: Thu Jul 22, 2010 6:22 pm

Pre-Amplifying low voltages with PicoLog1216

Post by reindyr » Thu Jul 22, 2010 6:58 pm

Hi all,

we want to use the PicoLog1216 to measure the current of the 12V bar of a Personal Computer's power supply unit. Therefore we created a test circuit to measure the voltage on a 10mOhm resistor. A typical range of values we observed in this setting is between 2 to 4 mV of voltage.

If I got it right, the resolution of the PicoLog1216 is 12 bit over the range from 0 to 2.5V, thus the smallest unit which can be resolved is 2.5V/4096 = 0.61mV. However in our setting we want to collect finer grained values to make accurate conclusions on the current drawn by the 12V bar (s.th. around 0.1 mV would be nice)

My question is if the PicoLog1216 can either preamplify the measured voltage or if it can distribute its resolution of 12 bit over a smaller range (e.g. measuring from 0V to 100mV with 12bit resolution.)

Thanks for help

Thorsten

ziko
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Location: St Neots

Re: Pre-Amplifying low voltages with PicoLog1216

Post by ziko » Mon Jul 26, 2010 10:28 am

Hi the Picolog 1216 or 1012 have a fixed range of 0 to 2.5V and as such your 12 or 10 bit range will be across the 2.5V range.

A more suited device is the ADC20/ADC24 which can take differential measurements (you can also offset your voltage to +12 V) and have higher resolution than the Picolog (at least 16 bits resolution at that range).

http://www.picotech.com/precision-data-acquisition.html

Hope this helps.
Ziko

Technical Specialist

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