PicoScope 7 Software
Available on Windows, Mac and Linux
Oscillating PicoLog 1216 readings
Oscillating PicoLog 1216 readings
Purchased a few PicoLog 1216 instruments for quality control purposes in
prototyping phase.
Voltage measurements start to oscillate after approx. 1h data acquisition.
Tried PicoLog v6 software on Windows / Mac / Linux platforms - all the same.
Changed power supplies in the system (injecting constant current into copper
traces to measure resistance under load) but the effect persists. Power cycling
of the data logger helps for about an hour, so the problem is squarely with the
device itself.
Google finds similar threads:
viewtopic.php?t=4502
viewtopic.php?t=40631
I need an explanation from company's experts before decision to equip ATLAS
Pixel Upgrade project with Pico 1216 data loggers (capital hardware purchase
for system upscale):
Voltage spikes are explicit for low readings, suggesting we face differential
non-linearity issue (racing ADC bits) which is temperature-related effect.
What kind of analogue to digit conversion does PicoLog 1216 utilise (flash /
successive approximation / Wilkinson type / sigma-delta) ? Do you apply
sliding scale linearization technique to your ADC readings ? Another potential
trap could be with the choice of sampling rate. I select 1s sampling interval.
Does it mean the software automatically goes into streaming mode ? Does it
oversample internally to produce robust average value at 1Hz rate ? Is there
any user control over statistical settings ?
prototyping phase.
Voltage measurements start to oscillate after approx. 1h data acquisition.
Tried PicoLog v6 software on Windows / Mac / Linux platforms - all the same.
Changed power supplies in the system (injecting constant current into copper
traces to measure resistance under load) but the effect persists. Power cycling
of the data logger helps for about an hour, so the problem is squarely with the
device itself.
Google finds similar threads:
viewtopic.php?t=4502
viewtopic.php?t=40631
I need an explanation from company's experts before decision to equip ATLAS
Pixel Upgrade project with Pico 1216 data loggers (capital hardware purchase
for system upscale):
Voltage spikes are explicit for low readings, suggesting we face differential
non-linearity issue (racing ADC bits) which is temperature-related effect.
What kind of analogue to digit conversion does PicoLog 1216 utilise (flash /
successive approximation / Wilkinson type / sigma-delta) ? Do you apply
sliding scale linearization technique to your ADC readings ? Another potential
trap could be with the choice of sampling rate. I select 1s sampling interval.
Does it mean the software automatically goes into streaming mode ? Does it
oversample internally to produce robust average value at 1Hz rate ? Is there
any user control over statistical settings ?
Re: Oscillating PicoLog 1216 readings
Please can you post a data file showing exactly what you are seeing, we can then look at your setup and why you may be getting these results. A picture of your setup would also help.
Martyn
Technical Support Manager
Technical Support Manager
Re: Oscillating PicoLog 1216 readings
Dear Martyn,
thank you very much for prompt reply and apologies for delayed response. I herewith would
like to inform you that oscillating readings were caused by flat panel monitor placed close
to the logging device with OPAMP adapter at the input for measured signals. The nature and
strength of radiated EMI noise was defying low pass filters.
One hour interval of silence after rebooting PC is still a mystery. The effect is common for
three different laptops: macOS / w10 / linux with various power saving settings. Moving
them all more than a metre away from the device under test solves the problem. To conclude,
PicoLog 1216 instrument itself is good for the purpose and I will be lobbyng its use in our QC
programme.
Regards, Ilya, 27/08
thank you very much for prompt reply and apologies for delayed response. I herewith would
like to inform you that oscillating readings were caused by flat panel monitor placed close
to the logging device with OPAMP adapter at the input for measured signals. The nature and
strength of radiated EMI noise was defying low pass filters.
One hour interval of silence after rebooting PC is still a mystery. The effect is common for
three different laptops: macOS / w10 / linux with various power saving settings. Moving
them all more than a metre away from the device under test solves the problem. To conclude,
PicoLog 1216 instrument itself is good for the purpose and I will be lobbyng its use in our QC
programme.
Regards, Ilya, 27/08
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