Accurate thermometers.
 

What kind of thermometers are everyone using? I have been trying out about 6 different ones and some are off by 8 degrees. What is the general rule for testing the accuracy of a thermometer for our temperature ranges. I was thinking of doing an ice bath of RO water to calibrate to 0 but I don't know how useful this would be in relation to our relatively narrow range.

I lke the JBJ digital, about $15. It matches the temp that my digital TDS meter reads.

Have you ever tried to check it against a know temperature somehow? How does one test or calibrate a thermometer?

I find the temp probe on my rK2 is very accurate. I have tested it against two different thermometers and it is within 1 degree. You can calibrate it as well if you find it is out a bit.

Allthough $300+ is an expensive toy if you are just going to use the controller for temperature :p

I do not think a degree here or there is all that important. 78 79 80 81 it doesn't matter. What is important is the swing. The steadier the temp the less the stress on the critter. If on the other hand the thermometer is out by 8 degrees through it out and buy a new one.

When ever I have bought a new thermometer I check all of them in the rack picking one out of the group showing the same temperature.

Tom R

When I bought my JBJ digital thermometers, I checked the rack which had about 10-12 of them on it, and I noticed a couple of them had a different number than the rest, so I made sure I didn't buy those ones.

I have one of almost every type monitoring my tank. Two digitals, one conventional and the cheapo stick on. They're all within a degree or so of each other. Need to remember that the location of the sensor/thermometer will have some influence over the reading. The sensor probes for my two digitals are closer to each of my two heaters than the conventional and stick on, so I expect them to read a tad higher.

Just do an ice point test. http://temprecord.co.nz/ice.pdf

I use a Fluke 68 IR Thermometer.----> I have it for work, so its easy and accurate.

I almost went and got one of those but I have this unfortunate problem with dropping stuff in buckets of water. I found a Cost Cutlery IR themometer in the fishing isle at Wally Mart for 30 bucks, not as accurate as the fluke I imagine but a much cheaper potential mistake.