Quote:
Originally posted by Groth
Here's a crudely drawn representation of my heat die concept. A cartridge heater (shown as red, such as the ones pH has - Watlow Electric?) is imbedded in a chunk of copper. Heat flows up the riser towards the water block. Two thermocouples are embedded into the riser at, say 10 mm intervals.
At steady state the temperature gradient up the riser will be linear and proportionate to the heat flow. Since we know the cross sectional area of the riser and the distance between the thermocouples, we can calculate the heat flow from the temperature difference. Additionally, we can infer the temperature of the die surface without having a probe directly on the die, avoiding the problems of a 'heat shadow'.
|
Thats a very smart idea, a way to measure power without the need of amp and volt monitoring. It has the advantage that it counts only the heat flowing to the die, independent of the possible secondary heat loses.
I'm too lazy to put some numbers on this right now, but the critical factor is going to be the temp probe accuracy, as the temp difference to measure can be small. But precicion of the readings can be increased with probes separation.