St. Croix and Gary,
No, there is no digital gauge, per se. It is analog.
The numbers are on a curve, going from 95 to 155 degrees with the gauge pointing at the right temperature.
I know that the designer test EVERY unit to insure the temperature is within a few degrees of what's indicated. If the production unit is not right, the tester affix a label adjusting the readings so they are correct.
FYI
- Brunswick does not want their balls subjected to heat greater than 125 degrees.
- Storm does not want their balls subject to temps above 140 degrees or below 40 degrees.
Other manufacturers may vary in their requirements,if they say anything at all. Brunswick and Storm both put the above requirements on (almost) every box.
I generally stick to the idea that was posted a long time ago: above 140 degrees resin and plasticizer (what makes urethane into resin) start to leach from the coverstock. I generally set my NuBall to 135 degrees. I have left balls in there at that temperature for over 5 consecutive hours with no harm, no foul, no cracking.