TM8812 Ultrasonic Thickness Gauge 1.2-200mm,0.05-8inch

Had it for a couple of months. It's simple to use, dependable, and provides accurate measurements (perhaps +/- 0.1 mm); it's actually surprisingly good, given its comparatively low price. Note that the nominal measurement range (starting at 1.2 mm) is given for iron / steel / aluminum. For materials with slower sound propagation (e.g., brass, copper, lead, plastics), the minimum range will be proportionately lower.

Worth the money for checking engine blocks since it has grey cast iron setting. Calibrate with included steel block and then switch mode for material. You will notice that checking calibration block with meter on a different material setting will not produce calibration value since block is steel. That's how you know it's compensating for material selection. Did some initial accuracy checks on grey cast iron surfaces that I could also measure with calipers. Has decent accuracy even when surface isn't machined. +/- .010 on an as cast surface. I found it to be within claimed tolerance on machined surfaces. Does not get a reading when shooting into an irregular shapes or too close to edges. I.E. extreme top and bottom of cylinders where casting material is transitioning. Once I knew it would work, I modified sensor to fit curvature of block for easier coupling of sensor. I put sandpaper in bore and carefully sanded sensor into approx shape. Keep center divider in line with cylinder length. Only sand enough so that coupling fluid has easier time taking up space. I used generic "personal lubricant, a.k.a. glycerine" and it's works well in any position. Manual recommends oil, but thicker glycerin seems to work fine.

Bought this to check for core shift on cylinder walls and wall thickness when porting cylinder heads. Measures the provided check disc perfectly but it is all over the place on cast iron and painted flat steel. The good thing is it shows it thinnner than it really is so you have a little wiggle room. Maybe as I get better with it, my results will improve but for example, the bulkhead on my 6.5 diesel block is 10.25mm thick. The machine says it is 10.1mm thick. I tried it on all settings just in case but it never gets more accurate than that. For the price, vs what a real sonic probe costs, it beats guessing like I normally do.

Wow. Thought I’d take the leap and follow the positive reviews. I’m definitely not one to buy cheap tools especially measuring equipment. Normally I only buy Mitutoyo and some older US made Starrett but this little gem is fantastic. It’s not perfect but is very accurate on grey cast iron and practically dead on with aluminum. I use it to check engine blocks and see bore thickness and main webbing thickness. Can’t beat it especially for the price.

This device worked well the first time I used it for testing. The second time the probe would no longer measure or calibrate. There are no phone numbers to contact anyone in the user manual. I returned the product.

So far so good. Great value, consistent so far, will follow up with more feedback. I use this on our Crude Oil Hauling tankers, not for certifications, but to help us make quick assessments in the field and when buying.

I bought this to help me decide when parts on my combine, and hopefully other farm equipment, are wore out. Most places where I can have catastrophic failures are difficult to measure any other way. So far it seems to work quite well. I would like a little bit more range on the low side, but it does measure within its stated range. I checked it on a piece of sheet metal against a micrometer measurement and it was within 0.010". Which is close enough for me. All I need it to do is tell me where I have good steel and where I have tin foil.

Seems like a decent tester. One thing I noticed is Amazon shows that a calibration block is frequently bought with this. There is a little round calibration block built into the tester right next to where the wires connect. Save your $80 and use the built in calibration block!