| Re: Paint Thickness Gauge, Cheapo Harbor Freight First Test Results.
Got my Colead Meter CM-8825NF. The operation of the unit seems almost identical to the Harbor Freight model. No trigger though - you place it on the sample and it beeps when it has made a measurement, or there's a continuous mode as well. I prefer the continuous mode, because I can place the unit down as slowly and gently as I like (to avoid scratching), and then wait for the measurement to stabilise. In single measurement mode, it needs to be placed quite "deliberately" on the surface.
Being the dual mode version (Ferrous & non-ferrous), it comes with two calibration substrates. It comes with four different thicknesses of calibration foils as well.
I didn't take any measurements of the area of my test panel that I polished before I did the polishing, but comparing the readings with other parts of the panel, I certainly haven't removed a lot of paint, which is to be expected because I didn't do any heavy compounding.
Trying the non-ferrous (NF) mode, I've discovered that for some panels of my car it gives a vastly different reading to those taken in F mode - circa 80um NF and 140um F. I'm pretty sure the 140um F-mode readings are the correct ones, especially seeing that on some panels it automatically switches to F mode if I had put it in NF mode, and then gives the same 140um reading as the other panels. Now, on my test panel (from the wrecker), it does a similar thing, however in NF mode it produces a much HIGHER reading than F mode - circa 400um NF, and circa 140um F. Again, I suspect that the F reading is the correct one. I assume that it would give valid readings on a panel which really was made of non-ferrous metal, however it's a bit of an inconvenience that it seems that the auto sensing of the material can't be relied on 100%.
I've contacted the supplier about this but in the meantime if anyone else has ever encountered this kind of issue I'd be interested. When I use the calibration substrates, it correctly senses the material and switches to the right mode.
Shipping (from China, I think, to Australia) was very fast indeed - five days from the Ebay transaction having being completed.
Greg.
Last edited by Skip : 06-06-2008 at 04:33 AM.
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Linear Mode
