GM100 Digital Ultrasonic Thickness Gauge Meter, Range 0.047 to 8.85in, for Measuring Metal and Nonmetal Aluminum, Zinc, Silver, Gold, Tin, Iron, Steel, Copper, PVC, Glass, Zirconium, Nylon

Everything I expected

I like this one a lot more the blue one.ihave had for about two years and still like it

I bought this to determine types of metals, such as silver or silver plate on steel, etc. This is done by measuring the sound velocity through the metal. The printed instructions tell you how to do this. The device does not work like the instructions tell you it should. The up and down arrow keys will not work as described. You cannot read-out the sound velocity so you cannot discern the type of metal.Also:Only reads out in mm, inches are not available.Key feature Sound Velocity Detection is not available to the user.When compared to a micrometer the thickness measurement of steel seamed to be very accurate.

This is an ultrasonic thickness measuring instrument that works quite well. It sends ultrasonic waves from its tranducer into an object, measuring the reflection time, and deriving the thickness of the object from that.It includes three AAA batteries which power the device. I wish it had an included rechargeable lithium battery as most of these small devices have nowadays.It includes a bottle of coupling fluid - it seems to be a gelled oil? Not quite sure what it is made from, but the unit WILL NOT FUNCTION if you do not use the coupling fluid.Turning it on, the unit self calibrates. You can add a drop of fluid to its metal calibration pad, put the transducer on it, and press the CAL button to calibrate the transducer.Now you select the appropriate velocity setting for the material you are measuring (there's a chart in the manual), apply the transducer, and it reads out the thickness of the object. A 4mm thick steel disc is included for testing/calibration.If you don't know the velocity for the material you are measuring, but have a piece of a known thickness, you can measure the piece, input the thickness, and the unit will derive a velocity, which you can then use to measure the thickness of other pieces made of the same material.All of this I had to more or less figure out on my own, as the included manual was written by someone who clearly has only very minimal competency in the English language. I have no idea why these companies refuse to hire someone to write their manuals who can actually write in the language they are publishing. As a result, a lot of the manual is incomprehensible, you have to try to guess what they are trying to explain.Other than that, the device works well, and is quite accurate when I tested against a micrometer.Who is this for?- Anyone who needs to measure the thickness of things, particularly large items where the back side is inaccessible and cannot otherwise be measured using a micrometerPros:- Accurate- Easy to use once you figure it outCons:- Atrocious manual is basically worthless- Uses AAA batteries (included) instead of internal rechargeable lithium battery- What happens when mystery coupling fluid runs out?

The unit is nice and compact lightweight and easy to use. The manual sucks has a lot of translation errors and miss wording. The unit does not change from metric to standard as listed in the Amazon description. The manual only gives information in metric and Celsius degrees and is misleading, but when calibrating on the block and a few items it read as accurate

Useful for determining the thickness of flat, clean substances of a known material. It measured within the accuracy of my caliper on a flat piece of aluminum.The round measurement lead is just over 1/2" in diameter (approx 12.1mm) and is circular. To get an accurate measurement, you the lead with the interface gel needs to seat against what you're measuring solidly to make the acoustic couple (connection).The manual has some serious translation issues and this is a fairly specific use case device so keep that in mind.I think the best use case for this would be measuring the thickness of pipe wall or metal stud of known material where you can't access both sides. In this scenario, it's going to be accurate after the struggle with the manual. The gel is available from multiple sellers (search for "Ultrasonic coupling gel").My hope was to use the device to help figure out the thickness and composition of items of unknown material so not so useful for me.