Review on UEi Test Instruments DM393: Auto Ranging CAT-3 TRMS Digital MultiMate - Accurate Measurements up to 1000V by Joz Lowe

Like Mr. Zang, I looked at the $100 DMM Shootout on Dave Jones' EEV blog and not minding the 'attractive' but robust field meter settled on the UEi DM393 with TRMS. And Mr. Zang is absolutely right, there's a protective film on the display (although you swear there isn't one!) that you have to peel off with your fingernail. Presumably the pull tab adds too much to the cost of the device! The unit comes with a good set of test leads, and the included alligator clips "screw" onto primary 18 AWG wire leads. I chose this DMM over all the others because it's rugged and you can access both the battery and fuses through a single compartment (metal threads rather than self-tapping screw) - all without breaking the calibration seals and without having to go inside the unit . circuit board. The battery/fuse compartment also offers additional protection in the event of a blown fuse. This is solid engineering/design from UEi in my opinion and an essential feature for any DMM. The AC/DC volts function defaults to AC - press the select button for DC. The 'Amp' function defaults to DC - press the 'Select' button for AC. The stand for desktop use is excellent and very stable, making it easy to flip the selector switch between functions. Both fuses are Type K fast acting ceramic fuses. Another highlight on the EEVBlog was that the UEi gauge had better 9V battery usage - up to 3.5 volts ahead of the low battery indicator (while the others were at 6-7 were!). The DM393 has a 4000 count "Resolution” display. I ran calibration tests right out of the box using the DMM Check Plus (AC/DC output) from voltagestandard.com (great portable product from Doug Malone!). The test included AC and DC voltage, AC and DC current (amps), four resistance values (from 100 ohms to 100 kohms), a 100 Hz generator and a 100 Hz duty cycle. All readings were accurate except AC (1.0 mA calibration with 0.96 mA instrument reading). Retesting still maintained a reading of 0.96mA, but on the microamps function the meter read 1006 microamps (AC accuracy specification according to the DM393 manual is 1.5% + 5). Conclusion (Although I'm not an electrician or an electrical engineer, but I know a little about electricity - that's scary!) - Excellent $115 TRMS DMM, and if it were a little "more attractive" Mr. Jones might have chosen it, not BK precision. unity ism! But as we all know, sex isn't everything. just say!