Pico Technical Support and Discussion Forum

Guest · Posted: Tue Jan 18, 2005 4:09 pm Post subject: signal conditioning

How does the scaling of input signals actually work? Is it purely by software, or is there a programmable gain amp in the data logger (ADC-16).
If it is purely by software (a scaling factor), isn't it best to level shift and amplify sensor output voltages so that they are nearly the full scale range of the input.
The ADC-16 input range is plus or minus 2.5volts, so a sensor voltage could be conditioned to be, say, plus or minus 2.4 volts.
Will this increase the resolution?

Sarah · Guest

Hi

Thank you for your post.

As you say, the input voltage of the ADC-16 is ±2.5V. Anything giving a voltage outside of this range would need to be scaled down using potential dividers. If the voltage is much smaller than this range then you could amplify it to give a better resolution of the signal.

The scaling that the software offers simply uses equations or look-up tables to change the input values to those of the real values. So for example if you were measure ±10V but had attenuated it, then the input voltages would be between ±2.5V but by scaling they could be displayed as still being ±10V.

Hope this helps

Best Regards

Guest · Posted: Wed Jan 19, 2005 10:56 am Post subject:

Thanks for the info. That was what I needed to know.

Regards

Dave

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