I have a PICO ADC-20 Data Logger and I have a problem with a strange behavier.
I have a mV source with 1000,0 mV output.
When I have only Channel 1 activated on the 2.5 V range and my mV source connected to Ch1 my readings in PicoLog Recorder are 1000,44 mV but if I also activates Ch2 on the 2.5 V range so I have Ch1 and Ch2 activated my readings are 997,40 mV on Ch1. I does not matter if I have anything connected to Ch2 or not, the reading drops 3 mV anyway.
This only happends on the 2.5 V range, not on the 1.25 V range.