LabVIEW
Voltage Signal Increases or Decreases randomly
Hello,
I am using a Kistler 9272 dynamometer, with a Kistler type 5011 Amplifier and a NI USB-6008 Acquisition board. My sampling rate is 1kHz and I am getting 300 samples. The total range of the dynamometer is around 5kN but I will be only using it untill 300N max. This is why I am trying to calibrate the transducer sensitivity to this range by loading static weights and measuring the voltage output. The following is what happens:
1) When the Amplifier is off the signal shows around 0 V (good!!!).
2) Turning the Amp on, the voltage slowly decreases. (what?, why?)
3) Loading a static weight of 0,5kg should give a response of around 0,17 V. Instead the Voltage peaks and decreases even faster.
4) After a while without moving or loading any more weights. The voltage starts slowly going up and stabilizes for a short period. (good, I guess)
5) But then, the voltage starts decreasing again.
At this point I gave up taking Screenshots and am totally lost. What could be causing this? Can I use this Dynamometer for static loads? If not what can I do to increase precision on this 300N range?
Attached: the vi I am using, dynamometer's and amplifiers' datasheet
Hi Rod,
you are using a charge amplifier.
Those devices are (mainly) meant for variable inputs. When you apply a static (or no) load it is prone to floating outputs.
See figure 1 in the amplifier's datasheet which shows drift and drift compensation influence. Read the full manual on your own…
