kevincwelch
New member
- May 12, 2013
- 2,686
- 0
We've seen some nice reviews and comments about the Nicety CM8801FN paint thickness gauge originally posted by zmcgovern45. It would seem that this is a nice inexpensive PTG that just about anyone could afford and use as a weekend warrior or as a full time detailer.
Towards the end of that thread, brondondolon asked about the AGPtek® Portable Car AUTO Paint Thickness Tester Gauge with Digital LCD by AGPtek.
So, I bought it and decided to test it against my CM8801FN.
First things first: please review the excellent testing performed by zmcgovern45. I am going to reproduce the table he created so you can review his testing and understand the margins of error.
Here's the extent of my "unboxing" photos of the AGPtek PTG:
Right away one notices the differences between the AGPtek and the Nicety in terms of size. The Nicety PTG fits nicely into my hands and is easy to use with two hands to balance the reader. The AGPtek is a little more cumbersome for larger hands.
There are also interesting differences in the probe. The Nicety has a probe that is depressed before the reading and the AGPtek has no such probe and simply reads when the device comes in contact with the paint. This creates a problem once you start using the AGPtek. Whereas the depressed probe and the raised circular flange of the Nicety allows you to make sure the device is perpendicular to the paint surface, the AGPtek takes a reading as soon as you come in contact with the paint. There is also a 1/2 second or second delay with the Nicety before the reading is taken, allowing you to make sure you are seated properly. This results in reading errors with the AGPtek.
The Nicety probe:
The AGPtek probe:
The AGPtek has two buttons on it: a "TEST" button and a "UNIT" button. The TEST button turns on the device and resets the reader before taking another measurement. The UNIT button switches between mils and millimeters. I found this to be a little disappointing since mils and micrometers are more useful to the detailer. Another problem with this device is that the value of the paint thickness is reported only in integers (no decimal points/values). So, an actual value of 3.4 mils would be reported as 3 mils and 3.6 mils would be reported as 4 mils. The problem with this is obvious: if your reading is 3 mils, is this 2.6 mils or 3.4 mils?
These are the product specifications
Here are the testing parameters. I used the ferrous and nonferrous discs and shims provided with the CM8801FN PTG and performed 10 readings each with the CM8801FN and the APGtek EM2271 as follows:
Next, I tested both meters on actual ferrous (2007 Subaru Outback) and nonferrous (2013 Tesla Model S). To ensure that I was reading the same areas each of the 10 times, I set up narrow field of view regions as follows:
Here are the results of the testing.
Test #1: CM8801FN Ferrous disc and shims
Test #2: EM2271 Ferrous disc and shims
(I suppose it's not a great start when your PTG measures 1 mil when in reality it should be measuring 0 mil.)
Test #3: CM8801FN Nonferrous disc and shims
Test #4: EM2271 Nonferrous disc and shims
As you can see, the results of the test indicate that the AGPtek EM 2271 is severely limited by its design. What I did notice is that as the thickness of the shim increased, the accuracy of the gauge improved; this makes sense when going back to read the specifications. In general, the standard deviation for the AGPtek EM2271 varied widely per reading of the shims, quite unlike the SD for the CM8801FN.
I was going to stop there, but I decided to run the test on the two automobiles anyway.
Test #5: Subaru Outback
Test #6: Tesla Model S
Summary
For $35 you can pick up a PTG called the AGPtek EM2271. The readings from this gauge improve with paint thickness; however, given the general range of automobile paint thicknesses (2.5 to 5.5 mils), this gauge may be insufficient for accurate measurement when it comes to paint correction. With a resolution of 1 mil and an error up to +/- 4 mils (see specifications), this leaves the user very uncertain of the actual coating/paint thickness. In reality, when I claimed that a reading of 3 mils might mean 3.4 mils or 2.6 mils, I'm not even sure that is correct (but it makes sense given conventional rounding practices); a reading of 3 mils could mean as little as 2.1 mils or as much as 3.9 mils.
Although more expensive and potentially a purchase risk, the CM8801FN (purchased off ebay from China for $150) provides consistent readings that are accurate within a very reasonable deviation from the mean.
A more conclusive test would be to assess the CM8801FN along side a more robust industry standard PTG such as those made by Defalsko. If readings from the CM8801FN are comparable to those made by the Defalsko, the CM8801FN would be an incredible bargain and robust enough to use as a daily driver for paint thickness measurement.
Therefore, the CM8801FN will find a permanent place in my detail cabinet; whereas, the AGPtek will enjoy its new location:
(Actually, I will try to return it; Amazon is good about those things.)
Thanks for reading and please comment or ask questions.
Towards the end of that thread, brondondolon asked about the AGPtek® Portable Car AUTO Paint Thickness Tester Gauge with Digital LCD by AGPtek.
So, I bought it and decided to test it against my CM8801FN.
First things first: please review the excellent testing performed by zmcgovern45. I am going to reproduce the table he created so you can review his testing and understand the margins of error.
Here's the extent of my "unboxing" photos of the AGPtek PTG:
Right away one notices the differences between the AGPtek and the Nicety in terms of size. The Nicety PTG fits nicely into my hands and is easy to use with two hands to balance the reader. The AGPtek is a little more cumbersome for larger hands.
There are also interesting differences in the probe. The Nicety has a probe that is depressed before the reading and the AGPtek has no such probe and simply reads when the device comes in contact with the paint. This creates a problem once you start using the AGPtek. Whereas the depressed probe and the raised circular flange of the Nicety allows you to make sure the device is perpendicular to the paint surface, the AGPtek takes a reading as soon as you come in contact with the paint. There is also a 1/2 second or second delay with the Nicety before the reading is taken, allowing you to make sure you are seated properly. This results in reading errors with the AGPtek.
The Nicety probe:
The AGPtek probe:
The AGPtek has two buttons on it: a "TEST" button and a "UNIT" button. The TEST button turns on the device and resets the reader before taking another measurement. The UNIT button switches between mils and millimeters. I found this to be a little disappointing since mils and micrometers are more useful to the detailer. Another problem with this device is that the value of the paint thickness is reported only in integers (no decimal points/values). So, an actual value of 3.4 mils would be reported as 3 mils and 3.6 mils would be reported as 4 mils. The problem with this is obvious: if your reading is 3 mils, is this 2.6 mils or 3.4 mils?
These are the product specifications
Here are the testing parameters. I used the ferrous and nonferrous discs and shims provided with the CM8801FN PTG and performed 10 readings each with the CM8801FN and the APGtek EM2271 as follows:
Next, I tested both meters on actual ferrous (2007 Subaru Outback) and nonferrous (2013 Tesla Model S). To ensure that I was reading the same areas each of the 10 times, I set up narrow field of view regions as follows:
Here are the results of the testing.
Test #1: CM8801FN Ferrous disc and shims
Test #2: EM2271 Ferrous disc and shims
(I suppose it's not a great start when your PTG measures 1 mil when in reality it should be measuring 0 mil.)
Test #3: CM8801FN Nonferrous disc and shims
Test #4: EM2271 Nonferrous disc and shims
As you can see, the results of the test indicate that the AGPtek EM 2271 is severely limited by its design. What I did notice is that as the thickness of the shim increased, the accuracy of the gauge improved; this makes sense when going back to read the specifications. In general, the standard deviation for the AGPtek EM2271 varied widely per reading of the shims, quite unlike the SD for the CM8801FN.
I was going to stop there, but I decided to run the test on the two automobiles anyway.
Test #5: Subaru Outback
Test #6: Tesla Model S
Summary
For $35 you can pick up a PTG called the AGPtek EM2271. The readings from this gauge improve with paint thickness; however, given the general range of automobile paint thicknesses (2.5 to 5.5 mils), this gauge may be insufficient for accurate measurement when it comes to paint correction. With a resolution of 1 mil and an error up to +/- 4 mils (see specifications), this leaves the user very uncertain of the actual coating/paint thickness. In reality, when I claimed that a reading of 3 mils might mean 3.4 mils or 2.6 mils, I'm not even sure that is correct (but it makes sense given conventional rounding practices); a reading of 3 mils could mean as little as 2.1 mils or as much as 3.9 mils.
Although more expensive and potentially a purchase risk, the CM8801FN (purchased off ebay from China for $150) provides consistent readings that are accurate within a very reasonable deviation from the mean.
A more conclusive test would be to assess the CM8801FN along side a more robust industry standard PTG such as those made by Defalsko. If readings from the CM8801FN are comparable to those made by the Defalsko, the CM8801FN would be an incredible bargain and robust enough to use as a daily driver for paint thickness measurement.
Therefore, the CM8801FN will find a permanent place in my detail cabinet; whereas, the AGPtek will enjoy its new location:
(Actually, I will try to return it; Amazon is good about those things.)
Thanks for reading and please comment or ask questions.
rops: