KleinTools MM700 57d86d8c87ae4

Tool Review: Klein Tools Auto Ranging TRMS Digital Multimeter

Dec. 2, 2016
The reviewer is impressed by the multimeter’s speed and accuracy.

The Klein Tools Auto Ranging TRMS Digital Multimeter, No. MM700, measures up to 1000V AC/DC voltage, 10A AC/DC current and 40 megaohms resistance, temperature, capacitance, frequency, duty cycle and continuity. It also has a low impedance (LoZ) mode for identifying and eliminating ghost or stray voltages. The MM700 is rated CAT IV 600V for safety, rated IP42 for water and dust ingress protection, and is built to withstand a 6.6’ drop. 

The review

“This is a full-function multimeter of the type that every technician needs,” says Phil Fournier, owner of Phil's Auto Clinic in Hemet, Calif., of the Klein Tools Auto Ranging TRMS Digital Multimeter, No. MM700. “I found it to be accurate and fast enough for the majority of automotive-type uses.”

Fournier used the meter for electrical troubleshooting, including the testing of the the ground circuit on a 2004 GMC Yukon with an intermittent problem on the electronic throttle control. He also employed the MM700’s min/max button to check the possibility of a volt drop on the TAC module ground wire, and he used the tool to check the operation of several oxygen sensors.

“This tool has all the functions needed by a technician, and even some rarely included in a tool of this price range,” says Fournier. “The fact that it does duty cycle, frequency, both AC and DC volts, and has a min/max feature make it an automotive winner.”

The tool arrived in plastic packaging, and accessories included voltage leads and the thermocouple. Setup consisted of selecting the voltage, frequency, duty cycle, etc., that he wanted to view every time the tool is turned on.

Fournier found that using the MM700 saved him the same amount of time on jobs as similar multimeters he utilizes do, and he says it was “fairly intuitive and easy to use.” He also appreciated the thermocouple’s accuracy and usefulness for temperature measurement, saying that it was well-suited for doing quick air conditioning diagnosis.

One suggested improvement Fournier has for the tool is that it should default to DC volts, as opposed to AC volts.

“You must press the SEL button to get to DC,” he says. “The indication that it is on DC rather than AC is also too subtle for my liking. I’d rather have it bigger and more obvious. I fiddled around several times trying to read voltage, and then I realized I was on the AC scale.”

Fournier also says he thinks the lead set for voltage could use some improvement, as he feels the leads are too short and the clips are inappropriate for automotive use.

“For automotive use, it should come with a better lead set with some good banana jack type clips and connectors,” he adds.

However, Fournier did come away impressed with the tool’s thermocouple and expects the MM700 to last quite a long time.

“The tool seems sturdily built,” he adds.