Amprobe AM-270 TRMS Industrial Multimeter with Temperature

Purchased this meter because it offered true rms, and the rarely found capability of sending data to a pc for analysis, as well as sensible feature set with a high accuracy, 6000 count 4+ digit display. I was not disappointed. Looked at Amazon reviews of dozens of meters. Plenty of cheaper ones with disappointing specs, and certainly very few with pc connection capability, which would replace my faithful 30 year old Radio Shack digital meter with an output to pc, but had only serial connector and software on 4 inch floppy so this feature was unused for many years.Engineers are not impressed with bloated advertising and overoptimistic and fake specs. This meter really impressed me. Much lower priced than traditional Fluke or equivalent top of the line units costing 2-3x as much as this one. Similarly, often vendors sell inferior digital meters with an impressive 4 digit display, of which only the top 3 digits are valid, and the least significant digit is totally insignificant due to high meter error, and where varying voltage or internal instability will cause it to dance around so much as to be unreadable anyway. This one has a 6000 count display where all digits produce useful readings.It is rare to find a portable meter capable of sending data to a computer. Be aware that this one has the "capability" via an optical output port on rear, but requires purchase of the accessory Amprobe connection kit USB-KIT3 sold here on Amazon. This comes with an optical connection to the meter, then to the supplied RS-232 connector which feeds a serial to USB converter, and includes a software disk with a Windows driver for the USB input, as well as graphics software that will display a data log, a copy of the meter's digital display, an analog meter graphic with a needle pointer, as well as plotting software that will display the measured value versus time as though plotted on a chart recorder. (Engineers love this stuff!) Further, I was able to easily print the data plot directly from this software, and also export the data log in csv format to Microsoft Excel, where a variety of impressive chart formats can be designed and printed, for example, for a technical report.I then tested the accuracy in the lab using calibration standards and the six digit HP bench meter with its 0.005% accuracy. Results of my tests were as follows:The Amprobe accuracy specification on this meter was easily met. In fact, the spec is very conservative, and the actual accuracy of my meter was well within the printed specification in most of my measurements.Temperature: cheap meters with thermocouple inputs are rarely accurate, but this one was within 2 degrees F at moderate temperatures (not at 800 degrees or more, of which the thermocouple is capable). My calibrated Fluke TK80 thermocouple module provided an output within a degree of the Amprobe. Note that for accuracy with a thermocouple conversion circuit in the meter, the meter case itself has to have time to stabilize to the ambient temperature, which may require 10 minutes.Frequency: I checked this against a lab signal generator, and found the 0.01% Amprobe specification to be valid. Unexpected.Capacitance: Did not care about this, but tested against capacitance calibration standards anyway. Most inexpensive meters provide this feature today, but it is of limited value due to inaccuracy, particularly if you need to check a capacitor that must be highly accurate for use in a particular electronic circuit, such as an oscillator. Accuracy confirmed from 0.8%+/- 3 digits up to .5mf and to 2%+/- 3 at 50 mf and even good to 5% for 10,000 mf electrolytics. Of course, to evaluate capacitor quality, you need a capacitor tester that can measure high resistance leakage values with the rated working voltage applied to the capacitor, which for some electrolytics could be hundreds of volts. Specialized capacitor testers can test for additional capacitor characteristics; a capacitance testing capability on a portable multimeter is useful, but should not be expected to tell you the whole story regarding a suspect problem capacitor.Continuity check: Instant loud beep tone, on making a continuity test. Loud, clear, and no delay. Low resistance values can be accurately measured by zeroing out the lead resistance by pressing the triangle, delta measurement marker. The delta button has other interesting uses, like zeroing out a large steady state voltage, forcing the meter to lower ranges to observe very small voltage variations. Works for shorts, and low resistance connections up to 200 ohms.Bar graph: Provides a bar graph with many segments, to display a representation of the voltage level. A zoom button, magnifies the sensitivity of this bar graph to 250 segments instead of 50 for observing subtle changes in meter readings which would be difficult to observing on a rapidly changing digital display.Digital display: full 6000 count capability, with a very large and high contrast display which I could easily read from over 10 feet away. Also the orange backlight is fully adequate to illuminate the display in dark areas. Push the light button for about 30 seconds of light.Warning beeps and messages: If you are on a range where you accidentally apply a destructive voltage, or measure an incompatible value for the particular switch position, the meter beeps a warning and will display a warning message. This is in addition to the internal fuse protection.Diode test: provides a low voltage to determine type of diode and if it is working. Not for LEDsCrest factor: Use to measure peak value, not rms. For example, power line voltage will provide a reading of 173v if CREST selected. Will beep when computation is complete. More useful when measuring non-sinusoidal waveforms, square waves, pulsed voltages, etc.Test leads: high quality rubber or silicone, not vinyl, with gold plated ends.

This is a great brand of multimeter and the best is the price , if you compare lets say with fluke.

On paper, this unit looks great. It has a great feature set and is rated to be much more accurate than similarly priced DMMs. Make sure you are OK with a meter this BIG. Unfortunately, it was defective out of the box. It took 45 seconds to settle on DC volts. It read 54Mohm with the leads shorted. Same results with a different set of probes and new battery. Amprobe tech support answered quickly and put me in touch with someone that sounded knowledgeable, but they did not have a functioning unit to compare against and said to return it, which I did.I decided to get a smaller meter and did not replace it.BTW: Compare the AM-270 with the Extech MP530A. Even the manuals are almost identical.

This is a very usefull meter. It works well and the meter does what the specs say it will do.

After much research and watching YouTube reviews I settled on this unit as being the best value. The temperature and capacitor functions will be great for my DYI HVAC and automotive projects. The only drawback, as mentioned in the YouTube review, is the continuity beeper is scratchy as though it does not latch in. This noise is a little annoying but any noise would indicate the circuit is closed, so no worries. It could be a bother if a circuit was cutting out intermittently since the meter does that as well. With what few tests I have done thus far this meter has been spot on and gets 5 stars for the great number of features to price point ratio.

its works well

It's ok & had a very good review for build quality/ safety on EEVblog, which is why I bought it. It has a horrible green backlight though, and just doesn't have the great feel of the venerable Fluke 87 - which is what I also bought afterwards.

good price for good tool !

Very good digital multi-meter. I recommend.

Just great. Recommended.