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

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.

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.

Nice inexpensive meter. Only things I don't care for is that there is no hinged stand on the back to prop it up in use. Also I prefer the test lead points sticking out of the insulation handle a bit longer. However it works well and isn't too large to hold in your hand.

Really good device

I already have the big brother to this meter and like it so much I tried this 4000 count one as well since the price is so low right now, I might like this smaller one a bit better than the larger one in some ways. For $17.99 and free shipping I simply have no real meaningful complaints, if any it would be the plugs would seem like they fit loose, but in all my testing and jiggling it does not seem to affect the electrical connection one bit, its just a result of matching this particular type plug in with the usual split jacks and the electrical connection itself doesnt show any effects from this it just seems to be the physical fit - ive never seen it affect the displayed number. I like this one as much or more than its big brother partly as this one has a better looking backlight. The blue backlight on the larger model has an odd washed out effect on the digits but the display is still very readable. This DT132A has a nice looking white backlight that I have no issues with other than like most it doesnt stay on long enough. As with its larger 6000 count brother theres a good deal of functionality here for the money, and ive found it very accurate in the main volt ohm cap ranges etc and it even reads temps without the thermocouple inserted if desired, and reads within 2 - 3 degrees - mine does at least. The continuity range has good volume, is reasonably fast and its even better after cleaning the tips with fine steel wool and alcohol. As with all meters in this price range theres little in the way of serious input protection, so use it accordingly its not an industrial plant meter its a home/hobby meter and given the price point and functionality im fine with that.

Great product, no question about it.

Great value. This is a really nice, high-quality auto-range multimeter. Comes with a battery installed and all ready to go. Nice, tough case. Good switch. Cheap and good!

Great for mA parasitic draw testing, I tested the leads for continuity but the readings were all over. I lightly sanded the probe surfaces and was able to get good readings. I also have the Astro cm4kor ac dc amp clamp and it's excellent for testing higher currents but I was unable to get good mA readings in series. I originally purchased the Astro DM6000AR but It was unable to read dc mA. I was sent a second one but had the same problem so sent them both back. This DT132A is great. Reads the same as my other good but older meter. I compared both volts and mA and both read the same. Great value for simple usable features. Between this and my amp clamp, I can troubleshoot many common electrical problems on vehicles. Took one star off for the leads needing attention but the are fine once you scuff them up