We tested the T12 Iron last week. We wanted to evaluate the consistency of the heat throughout the base, the accuracy of the temperature read out, and the tightness of the thermostat window. We used a PYRO Digital 250 series Digital Pyrometer (contact style) which is basically a fancy thermometer which in our case was accurate to .01 degree.
We tested 3 different T12 irons. We tested with the temperatures set to 266F, 300F, and 320F. We took temperature readings toward the front, in the middle, and toward the back at each temperature setting. Spot checking the temperatures was not very practical due to the thermostat window. That said, the temperatures were pretty accurate (within 5 degrees F on average). It also depends on whether the iron is touching the base or a chunk of wax which cools it off compared to if it is just sitting hot without the base touching anything.
We were able to establish that the forward part of the iron was hotter than the middle which was hotter than the rear part. This is because the heat element is toward the front. The base plate is thick enough that the heat is distributed pretty evenly, but there was about a 3 degree variance on average.
Then we touched the sensor to the middle of the base, held it there, and watched the temperature variance. This was to establish the thermostat window. When an iron is set to a particular temperature, it heats up until it hits that temperature and then turns off. Once it cools to a particular degree, the thermostat kicks the heat element on and it heats up again to a preset temperature and again shuts off. This cycle is repeated again and again. The difference between the lower and higher temperatures is referred to as the thermostat window.
One also has to take into account the fact that when an iron is being used, heat is lost through contact with the wax or the ski. If the iron is being tested without being touched to a ski or a block of wax, it will surely be warmer than if it were. We tested the thermostat window by touching the temperature contact sensor of the Digital Pyrometer to it and holding it there. This brought the temperature down (the first cycle was hotter as the base hadn't been touching anything previously). We had the iron set at 300F. The thermostat cycled the iron between 298F and 309F. Had the contact sensor been the ski base or a chunk of wax, the iron would have certainly been a few degrees cooler centering the variance on the desired temperature. So, we were very satisfied with the performance of this iron.
With a retail price of $132, this is clearly the best performing and least expensive digital wax iron on the market.