AstroAI Digital Multimeter, TRMS 4000 Counts Volt Meter (Manual and Auto Ranging); Measures Voltage Tester, Current, Resistance, Continuity, Frequency; Tests Diodes, Temperature (Red)

Great multimeter, works great and seems to have good quality.

I use it almost every day, to see if I am still alive....kidding. Just a great meter. I use it on the boats (nightmare), electronics, vehicles etc. Had it for years and if you turn it off the batteries will last a long time. This is not like a brain surgery review. Volt Amp meters work, this one is my go to and reasonably priced. I have abused, dropped and whatever you can do to a meter and this keeps doing it's job. This is not an AI review. I am responsible.... Caveat-Don't loose the little screw when you are replacing the batteries...hard to find if you are as old as me.

Good meter except for the fact that the backlight times out after about 10 seconds. I contacted customer service and they recommended a replacement meter that would not time out the backlight. DM6000AR is the model.

Indispensable tool. Great value.

After an intense review of what was available in the digital multi-meter (DMM) product space, I purchased four AstroAI TRMS 4000 meters based on competitive pricing with similar products with similar specifications. These multi-meters were purchased for use by middle and high school students that are participating in the National Science Olympiad program. The features that were required were simple to use, has an easy to read display, is both precise and has acceptable uncertainty, in a physical package that could withstand the abuse/misuse of the students. Most of the digital multi-meters in this same price category, as the TRMS 4000 were NOT auto ranging or too small to have a reasonable size display. The meters with similar features by Fluke, Extech and Amprobe, to name a few, varied in price from ten to twice as expensive. Since I needed four, all of those meters were immediately ruled out. When the TRMS 4000 meter arrived, a quick physical, hands on inspection, revealed a solid design that was well labeled, with an LCD display that was about the same size as my personal hand held Fluke DMM. To test the meters, I used a variety of batteries and precision one-percent resistors to compare the performance of each meter, against my Fluke and against each other. In all cases the TRMS 4000 meters within +/- 4 least significant digits in the three and a half digit mode and +/- 2 least significant digits in the three digit mode. Without doing any real statistical analysis and without true NIST traceable standards, I feel comfortable that these meters were precise with an uncertainty that was within 1% +/- 1 digit in the tested ranges, which seems to correlate well with AstroAI’s stated specification. I should note that the results I obtained with precision resistors was well within the stated specifications. Since these we to be used for Science Olympiad competition, and the general rules prohibit using dangerous voltages, I did not test the AC or higher DC voltage ranges. However seeing the excellent results with low voltage DC and resistance, I would feel comfortable using one of these as troubleshooting tool in a professional capacity on low frequency equipment and appliances. Because TRMS 4000 has a specified input impedance of 10 Meg Ohms, I would not recommend this for use on sensitive instrumentation or high frequency circuits where test input impedances > 100 Meg are recommended and generally required. I would also recommend not using any hand-held multimeter for directly measuring currents in excess of 1 amp even though they may be equipped to do so, external shuts should be used for these types of measurements. In summary, for the price, this is an excellent choice for the serious hobbyist and student. If I had it to do over, I would still purchase these DMMs.

Initial impressions are good. I have owned a half dozen or so meters in the under $50 category and this is by far the nicest and most feature packed. The little things that others have complained about like the beeping and the quality of the leads don't bother me. In fact these are probably the best set of leads I have ever gotten, in terms of length and stiffness/plastic-y feeling. I like the sleeves on the tips as well. They fit secure and help prevent accidental bridging in tight spaces. Accuracy seems good enough for me. I am not necessarily doing high precision work with this unit. It will mostly be for testing batteries and repairing/troubleshooting home and automotive electrical. I appreciate that this unit measures temperature and I have already used that function. I haven't had that feature before. I also like knowing it will test capacitors, diodes, and does true RMS and Duty Cycle. My only wish is that it had the magnet leash like the 6000 model, but that's no deal breaker. I am very pleased with this unit.

This is an inexpensive meter so don't expect Fluke-like performance and durability, but for the majority of us who don't use a meter enough to justify the cost of a Fluke it works very well. It's more than capable of bench work and troubleshooting vehicle electrical systems, but for HVAC or heavy use you need something a bit more robust. This is for weekend DIY'rs. If I'm going to use a meter it must be quick latching. Any meter can provide Volts and Ohms and Amps, but if I'm checking continuity I want instant feedback. This isn't instant but it's very close. I replaced the leads and actually prefer using this meter over some of my larger and more expensive ones. Overall I'm very satisfied with the size and performance.

I've had the AstroAI DT132A multimeter for just a few of days so far and can report some impressions. First, it is astonishing the features packed into this DMM: auto/manual ranging, min/max, relative measurement, hold function, temperature, true RMS and 4000 counts. All for $23. We owe all that to the single DreamTech DMM chip inside. The same chip is used for many brands of meters. I have not opened the case but from viewing a teardown video, the innards are sparse indeed with few other components but it does look to have some input protection components. For my use the 4000 count display is more than adequate. In many years of electronic work only a few times have I needed more than the four digits of precision that this meter provides. The single sheet manual with microscopic font size is adequate but barely. Note that the 145x70x35mm dimensions it gives for the meter are incorrect. If you're shopping for a case, the actual dimensions are: 155x75x35mm. Many, if not most, multimeters have separate banana jacks for current measurement vs. the voltage, capacitance, etc. combo input jack. This meter does have a separate input jack for the 10A current measurement but it uses the combo input jack for uA and mA current ranges. The good: convenient to not have to unplug and re-plug for a current measurement. The bad: if the probes are connected to measure a voltage, say with alligator clips, and you even momentarily switch the rotary switch to the uA or mA setting IT COULD FRY THE METER. At best it would blow the 500mA fuse, at worst it could burn the circuit board. The instruction sheet does state: THE MANUAL ROTARY SWITCH SHOULD BE PLACED IN THE CORRECT POSITION BEFORE MEASUREMENT AND SHOULD NOT BE MOVED DURING MEASUREMENT TO PREVENT DAMAGE TO THE METER. Some reviewers have complained about the beeping at every setting change. I like it because some SELECT button settings don't apply to some rotary switch positions so it will not beep for those. The beep provides some feedback that the setting will be applied. It does have the red outer moulding of soft-ish plastic, but it's only 0.1" thick so it will provide only minimal protection in a drop. The kick stand is flimsy and easily bendable. One surprise is that it came with the three AAA batteries installed--not just placed in the box. As other reviewers have stated, the backlight stays on for only 15 seconds then the button must be long-pressed to re-light. If you need to use the meter in low-light environment you'll get tired of that. If there is some cryptic button sequence that changes that timing, I'd like to hear about it. Overall, it's a remarkable feature-rich meter at a bargain price but with flimsy construction. I'll subtract one star for the thin rubber overmould and backlight timing.