Malfunctioning Thermometer?

[MandyK]

Yesterday I bought a new digital thermometer. The kind that hangs on the outside of the tank, and has a probe that you submerge in the tank.

Well it's reading 73F! This is confusing me, because my regular glass, mercury thermometer is reading 79F. Soooo which one is screwing up?? I mean if I go get a new heater and turn it up so that the digital reads 79, and I kill my fish because the thermometer was screwed up I'll be heart broken.

What's going on??

[Drumachine09]

Is there a dial to calibrate it? Every digital thermometer I've had required calibration.

[MandyK]

Hmmm, I'm not sure. I'll have to take a look. About where should it be located?

[Drumachine09]

Mine have always been on the back, or under the battery cover.

[MandyK]

Okay, there isn't one that I can see. The only thing under the battery cover is the battery.

Is it possible that the other thermometer is wrong?

[Drumachine09]

Either one of them could be wrong, just because one is fancier than the other doesn't mean it is more accurate. Without a properly calibrated thermometer to test them against, its pretty hard to determine which is correct.

Only other thing I can think of is maybe the thermometers are at different ends/depths of the tank, causing different readings.

[MandyK]

That's the thing, they are both in the same general area. I did that on purpose to make sure they would read about the same. Low an behold... Lol.

The digital one isn't what I would call fancy. I was trying to go for something that gave me faster results, and now I'm in this mess!! It was only $10.

I think maybe I'll get a heater that has the actuall temp settings on it. That may help me figure this out.

[MandyK]

Figured it out! The display is messed up. It is actually reading 78... lol. For some reason those two line that would make the 8 don't work. Phew!

[Drumachine09]

Ha, what are the odds of that! Glad you got it figured out. Stuff like that can be incredibly frustrating.