I am currently using a polyamide heater to heat 6 small wells for my device; however, the heat across the heater is not the same. Is there a heater that is good for high accuracy (there will be a controller element, so this might not be applicable but I am not sure) and even heat spead? I am trying to heat the wells above the heater to 37C. I have tested 12V and 5V heaters, and prefer 12V for the higher ramp speed, but I am flexible. Smaller heaters are also preferred; however, again, I am flexible.
Hello eheckard3,
I was able to find a few that run on either 5 or 12V, you can see all of those linked HERE. Some of those are rated for a temperature quite a bit higher than you mentioned. The ones that I found that are rated for up to 65C can be found HERE. Looking at the manufacturers page, they do mention that they have uniform heat distribution, but do not see a mention of their accuracy.
What exactly is meant by this? Some near-field non-uniformity will naturally occur due to the patterning of the resistive element, but on balance the thermal flux per unit area of such devices tends to be quite consistent. Uneven temperatures will result from that however if are spatial differences in the rate at which heat is escaping from or being absorbed within the system.
There’s a high probability that the meaning of these figures is not being correctly understood.
Resistors (which heaters of the type basically are) don’t really care what voltage is applied, so long as A) they’re kept sufficiently cool and B) that voltage is not so high that it causes an electrical insulation failure. Point (A) is most often the limiting factor, but any number a person might attach is meaningless unless the thermal conditions that it’s based on are defined. Heaters designed for equivalent output at 5 or 12V respectively should exhibit little to no difference in temperature ramp rates between the two, because the power dissipated is the same. If one takes two identical devices however and applies 5V to one and 12V to the other, the one operated at 12V will naturally increase in temperature more quickly because it’s burning off nearly 6x the power of the other.
Since I am using a temperature controller and probe system, does it have any impact what the temperature is rated for. Also, does the rated temperature impact heating speed?
Best,
Emily
The temperature rating on film heaters typically indicates a maximum permitted operating condition, which should not be exceeded. It has no direct bearing on heat production/transfer characteristics, aside from establishing an upper limit of such.