can we log DC current surge in micro ampere for initial 20ms using @34972A? If yes please explain how to do it.
the 34972A with the 34901A module, can read DC current in μA on the 10mA range with a maximum speed of 500 readings/sec or 2ms/sample (scan one channel only), however the measurements will be more noisy because the device will be in 4½ digit 15 bits. To answer correctly, give more details: you say "initial 20ms", is it the period of measurement or the width of the surge?
I want to measure the DC current surge when we power up the UUT for the very first time from fully de energized state. The interval I want to measure Is for first 20 milli seconds from t=0. "It is the period of measurement".
I have both 34972A and 34901A available with me.
Could you please provide me the setup diagram if possible?
there are no special setup or diagram, simply use 34901A port #21 or #22 to measure current (no external trig possibility), you must start acquisition with your 34972A, and powerup your UUT after or use of SCPI commands to start a sequence to control Power supply and 34972A.
The 34972A is a great instrument but it have serious limitation for your measurements setup because the period of test is 20ms and sampling rate is around 2ms, or 10 samples only during this period. If the surge is smaller than 2ms, maybe it will not possible to detect it.
IF DC current monitoring is the DC power of your UUT, they are better instruments to do that, for example: (see information below). For these DC sources, sampling rate is programmable form 15µs to 31,200sec. With 15µs for your test, you would have 1333 samples instead of 10 with the 34972A...big difference.
Mobile communication DC Source
I used a vb.net program to test performance of acquisition on 20ms period with max sampling rate (around 2ms, but not constant). Here are the SCPI commands that I used:
*RST 'reset instrument
*CLS 'clear error list
ROUT:SCAN (@121) 'create a scan of one channel, here 121 (slot#1 and port #21)'
CONF:CURRENT:DC (@121) 'configure port #121 in current DC measurement
SENS:CURRENT:DC:RANGE .01 (@121) 'set current range for 10mA
CURRENT:DC:NPLC .02 (@121) 'set NPLC to 0.02, 4½ digits (faster sampling)
TRIG:COUNT:100 'take 100 measures for total of around 200ms
INIT 'start measurement
FETCH? 'read DATA
I hope this information can help you.
Thank you Tardz.
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