Recently, Rigol released a new DMM series, the DM858E and DM858 models. Both of them are 5-1/2 digit DMMs. As they already have 5-1/2 and 6-1/2 digit offerings, I thought I'd be interesting to compare these to each other and to other DMMs on the market.
The differences between the E and non-E model are that the E model has 0.06% vs 0.03% DCV accuracy, can store only 20K readings vs. 500K, and does 80 readings a second vs. 125 readings a second. Additionally, the E model lacks the 10A input jack. It can only measure up to 3A. They retail for $370 and $500 USD, respectively.
It should be noted that I'm including the Keithley just to give you an idea as to what a really powerful DMM in capable of. I converted the PPM readings to the typical XX% + YY% (reading + range).
| FLIR DM93* | DM858` | DM3058 | DM3068 | Keithley 2001^ |
DCV | 0.05 + 1d | 0.03 + 0.004 | 0.015 + 0.003-4 | 0.0035-55 + 0.0005-10 | 0.0024-41 + 0.0002 |
DCA | 0.2 + 2d-10d | 0.055-0.250 + 0.005-20 | 0.055-0.250 + 0.005-20 | 0.007-0.1+0.002-20 | 0.04-9 + 0.0020-25 |
ACV (50-60Hz) | 0.5 + 2d | 0.2 + 0.1 | 0.2 + 0.05 | 0.06-8 + 0.03-4 | 0.1-0.07 + 0.015 |
ACA | 1 + 2d | 0.05-3.00 + 0.02-5 | 0.3-5 + 0.1-2 | 0.10-15 + 0.04-6 | 0.20-15 + 0.015 |
Ω | 0.2-2.0 + 1d-20d | 0.05-3.00 + 0.02-15 | 0.02-25 + 0.003-5 | 0.01-4 + 0.001-4 | 0.005-4.000 + 0.0004-0.1 |
The overall conclusion I can draw is that you should buy the DM3058 over the DM858. The E model and a good handheld DMM are kind of a toss up. The DM858E is better at ACV, but worse DCV accuracy, and the shunts for both DCA and ACA are rather restricting.
Well, I hope you enjoyed the write up. What are your thoughts?
* This is the DM93 original. They have since released a DM93-2 with worse accuracy. Oddly enough, it's also bigger and heavier. These counts are for the 3-3/4 range, not the full 4-3/4 range as it's accuracy specs are not listed in the datasheet/manual. I could have chosen a Fluke 287 for this chart, but the accuracy of that meter is largely worse than the DM93.
^ Yes, the resistance accuracy really does drop off for the Keithley 2001/2, but then the range at that level is 1Gohm; which is well above what the other DMMs can do.
` It should be noted that the burden voltage of this DMM is well above the average 100ohms. The DM858 uses a 330ohm shunt for the 100uA-1mA range, a 3.3ohm shunt for the 10-100mA range, and a 0.008ohm shunt for the 1-10A range. What good is accuracy if the burden voltage is over 3x other meters?