I seem to be having a triggering problem in the ‘single’ mode. It’s probably my lack of experience with this firmware.
Triggering:
I am looking at current draw at power on of a device. I have a 10 ohm resistor in series and I’m measuring voltage across it with the DSO Nano. First of all, and correct me if I’m wrong, but the trigger level seems to change depending on the volts/div setting which is frustrating. I get the unit set up to trigger and display a waveform. I change the Volts/Div, repeat the power-on event and no trigger, try the event again and sometimes I get a trigger. I have to go back and play with the trigger level to get it to work. I spent 80% of my time trying to get the DSO Nano to trigger properly on a single shot positive-going waveform.
Trigger sensitivity is a mystery to me - I have never seen that function on a DSO from a major manufacturer (but I have only seen Tektronix and Instek). Can anyone explain this to me? This could be a large part of my problem.
Calibration:
I tried to cal the unit and the results were strange. Should it be cal’d using AC or DC as an input? If AC then I would like to see a RMS as a measurement in the 'ME" screen. Using DC I can cal it to one voltage (for instance 1V on the 2V/div scale), but when I apply 5V DC to the input the reading on the DSO is wrong by at least 0.5V or more. Here is an example of my results calibrating the 2V scale with 10V DC input:
Input V(DC): DSO Nano Vavg reading:
1V--------------------2.24V
2V--------------------3.04V
5V--------------------5.68V
8V--------------------8.24V
10V-------------------10V (Cal Voltage)
Again, I assume that my problems are due to my lack of experience with the DSO Nano. Can anyone tell me what I’m doing wrong?
Thanks,
Tim