CTC thermocouple

[EagleSeven]

I wanted to print with the bed heater off but I can't find a setting in makerbot program to turn it off during print.
I just set it to 30deg. then noticed, when the print wouldn't start, that the display was showing 40deg when the printer was cold.
So I see when I first turn on the machine and check the temps monitor the two extruders are at 29deg. and the bed is 40deg. Since it's 29deg here today then two of them are correct.

Does anyone know how to calibrate the bed thermocouple on a CTC 3D printer ?

You will need another accurate digital thermometer with thermocouple-probe
to get an accurate temp of bed.
The bed-temp circuit on Mobo will not read accurately below about 50C

Using digital-meter, I found that temp on top of glass-plate is about 12.C lower than at the metal-plate below it, also.
So if using a glass-plate on bed, like you should, then adjust temp up to compensate for that difference.
I found that setting of 85.C, for bed, is good for PLA filament,
which is about 73.C on top of glass.
(center of bed gets a little hotter than outer edges)