Rigol DL3021A low current setting error

[atx]

When testing small currents, for example, currents less than 10 mA, my DL3021A does not apply the correct current until it reaches 8 or 9mA, then when dialing back to 0mA it seems to work until you reach 0mA then the trouble starts over.
For example, setting the load to 0mA applying a source voltage 3.3V shows:

current setting    read value  (manually increasing by 1mA)
=================
0.000A               0.0021A
0.001A               0.0022A
0.002A               0.0023A
0.003A               0.0023A
0.004A               0.0023A
0.005A               0.0024A
0.006A               0.0024A
0.007A               0.0025A
0.008A               0.0025A
0.009A               0.0095A  <- trigger point
once this point is reached it will work when dialing backwards until the error message at 0mA is shown then the same behavior repeats. 

The general offset of 2mA is already bad, but this hysteresis behavior is really annoying.  Range is set to 4A but it does not make a difference if set to 40A.  Slew rate changes make also no difference.
Anybody got the same erroneous behavior?

atx

[kwinz]

Were you able to resolve this problem in the mean time?

[TurboTom]

... so it seems Rigol didn't improve that much on the DL3000 accuracy in the last two years. You may want to compare your findings with mine (and other's as well) in this old thread.

If you need the load specifically for low current applications and you're still in the time window of returning it, you may consider to do so. There are much better loads around for low power measurements.

For high, non-changing currents though, the DL3000 may be a decent choice.

[joad]

Hi, does anyone know how to calibrate the DL3000?

I can see some interesting SCPI command, but I cant se the whole picture.
All ideas and tips on how to do this are gratefully appreciated.

Code: [Select]

0096 - STARt            STAR        :CALibration:STARt
0097 - END              END         :CALibration:END
0098 - END?             END?        :CALibration:END?
0099 - OFFSet           OFFS        :CALibration:OFFSet
009A - OFFSet?          OFFS?       :CALibration:OFFSet?
009B - SAVe             SAV         :CALibration:OFFSet:SAVe
009C - DAC              DAC         :CALibration:DAC
009D - DAC?             DAC?        :CALibration:DAC?
009E - CLEar            CLE         :CALibration:DAC:CLEar
009F - ADC              ADC         :CALibration:ADC
00A0 - ADC?             ADC?        :CALibration:ADC?
00A1 - CLEar            CLE         :CALibration:ADC:CLEar
00A2 - RANGe            RANG        :CALibration:ADC:RANGe
00A3 - RANGe?           RANG?       :CALibration:ADC:RANGe?
00A4 - AUTOrange        AUTO        :CALibration:ADC:AUTOrange
00A5 - IMON             IMON        :CALibration:IMON
00A6 - IMON?            IMON?       :CALibration:IMON?
00A7 - STATe?           STAT?       :CALibration:IMON:STATe?
00A8 - VMON             VMON        :CALibration:VMON
00A9 - VMON?            VMON?       :CALibration:VMON?
00AA - STATe?           STAT?       :CALibration:VMON:STATe?
00AB - VALid?           VAL?        :CALibration:VALid?
00AC - OCP?             OCP?        :CALibration:STATe:OCP?
00AD - OVP?             OVP?        :CALibration:STATe:OVP?
00AE - OPP?             OPP?        :CALibration:STATe:OPP?
00AF - RA?              RA?         :CALibration:STATe:RA?
00B0 - GET?             GET?        :CALibration:DATA:GET?
00B1 - CLEar            CLE         :CALibration:DATA:CLEar
00B2 - CCOFfset         CCOF        :CALibration:BIASref:CCOFfset
00B3 - CCOFfset?        CCOF?       :CALibration:BIASref:CCOFfset?
00B4 - OPPRef           OPPR        :DEBug:BIASref:OPPRef
00B5 - OPPRef?          OPPR?       :DEBug:BIASref:OPPRef?
00B6 - OVPRef           OVPR        :DEBug:BIASref:OVPRef
00B7 - OVPRef?          OVPR?       :DEBug:BIASref:OVPRef?
00B8 - OCPRef           OCPR        :DEBug:BIASref:OCPRef
00B9 - OCPRef?          OCPR?       :DEBug:BIASref:OCPRef?
00BA - RARef            RAR         :DEBug:BIASref:RARef
00BB - RARef?           RAR?        :DEBug:BIASref:RARef?
00BC - VMON             VMON        :DEBug:BIASref:VMON
00BD - VMON?            VMON?       :DEBug:BIASref:VMON?
00BE - IMON             IMON        :DEBug:BIASref:IMON
00BF - IMON?            IMON?       :DEBug:BIASref:IMON?