https://www.eevblog.com/forum/testgear/sdm3045x-versus-dm3058e-sensor-input-4-20ma/msg3793730/#msg3793730 and subsequent post. Can confirm there is no custom sensor option in the menu on my 3055.
@Dbldutch
I'm seeing weirdness about the LO terminal of my DMM as well. I have a Siglent 3065X-SC, still in the return window and I'm very disappointed with this finding.
I was not expecting the LO terminal to be grounded, let alone with a potential of 13.33V from the earth.
The 'HIGH' terminal also has a potential to the case.
A DC voltage between ground and the LO terminal is indeed unusual. 13 V with the usual 10 M input resistance for the 2 nd DMM would be some 1 µA of current. It is normal to see some current there, but this is normally a AC current from capacitive current. I don't know how well the Fluke DMM handles a large supper-imposed AC votlage in the DC ranges - the shown DC voltage may actully be an effect of the Fluke meter. It may be better to use the scope to measure the voltage. The interesting part would be more the AC part.
There could still be a weak point with the SDM3055 in a relatively with a large AC part.
I'm seeing weirdness about the LO terminal of my DMM as well. I have a Siglent 3065X-SC, still in the return window and I'm very disappointed with this finding.
I was not expecting the LO terminal to be grounded, let alone with a potential of 13.33V from the earth.
The 'HIGH' terminal also has a potential to the case.
I'll reach out to the seller for a fix.
If I measure current with Fluke from shell to LO I get some 60-70 mA
With the help of TestController I can't achieve faster readings than 3/sec.
thanks for your hints, but unfortunately it doesn't work for me. I tried all your advices but the limit is always about 6...7 readings per second.
The SDM is LAN-connected. I went down to 0.05 PLC, manual range 2VDC, no Auto-Zero but no chance to get faster readings.
btw: I exported the table of measurements to EXCEL and did there the FFT. Is a FFT function in Text Controller in future something you are considering?
Resolution, and Accuracy is not the same thing :-) no surprise
if I get access to another instrument, with 10 times the resolution and 10 times the accuracy
is there an easy way to tweek the numbers, so they read the correct value ?
or do i need special equipment, and special procedures to perform calibrations ?
two SDM 3055 side by side
ultra clean and stable 5V input
been like this for 7hrs straight
both brand new
Resolution, and Accuracy is not the same thing :-) no surprise
if I get access to another instrument, with 10 times the resolution and 10 times the accuracy
is there an easy way to tweek the numbers, so they read the correct value ?
or do i need special equipment, and special procedures to perform calibrations ?
It‘s astonishing how good my old HP still is and also how good the SDM is (beside the other weaknesses).
I‘m pretty sure that the HP will do it another 20y, and we will see how the SDM will behave.