Measurement Computing CIO-DAS16/330 - Manual (Page 32)

6.7.3 SENSOR NOISE
When the signal wires have been tested and characterized for signal quality, connect the sensor and provide a known
level to the sensor (ice bath for temp., etc.) then take data for the histogram plot. If additional noise has been introduced
by the sensor which exceeds the sensor specifications, you can try moving the sensor or electrically isolating it from the
device it is measuring.
6.7.4 SMOOTHING DATA
It is not always possible to eliminate all noise, especially with very low level sensors, but noise when plotted is
undesirable and can raise doubts about otherwise excellent data.
There are two simple ways to eliminate noise from the data:
1) Apply a moving average to the data if you want to retain the same apparent accuracy.
2) Remove the information from the noisy range. For example, if the A/D is capable of , or, shift the data by the number
of counts of noise. For example, if a 12-bit A/D converter is at +/- 5Volts (10Volts full scale) then one LSB = 10 / 4095
= 0.00244mV. If your system is inducing +/- 0.007mV of noise (+/- 3 counts), then round all the readings by +/- 3
counts. In this way the reading's value reflects the true accuracy of the system.
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