I'm noticing that the 0-10v output from my sensor is not as stable as I'd expect or like. the sensor is a distance measuring device and although I'm expecting a slight variation, what I'm seeing is unworkable in my current application.

When I measure the output with a voltmeter, I see as expected and see the expected variance when I simulate distance measurement change but when connected to my logging software instead of seeing a stable volt reading, I see occasional peaks and dips (this might be at the same frequency), thinking possibly a by product of the AC-DC conversion?

Anyway, I'm using a decent 24v DC power supply and the sensor without mentioning brands is of good quality, as is the logging equipment and software so...

Is this variation the kind of things I would expect to see and if so, should I be considering a smoothing capacitor or something?

All help appreciated...

 

You have nearly solved your own problem. I would indeed check the power supply with a scope as a meter tells you little about pulses. I would try a large (10-100 uF or more) capacitor across the supply close to the device to see if its a line impedance problem. Your datalogger is experiencing the scourge of the digital age, any single sample may not be the one you want. Your meter handles it the human analog way, it averages it. If possible, you probably want to do the same either digitally or with an analog filter. It's not very often you can use a single reading except from very stable or heavily filtered sources. It's the nature of the beast. A 14 bit A/D reading a signal with 10% jitter is lying all the time.

Regards
cww