Thermometers

[ramblin101]

I'm having a hard time gauging readings on my thermometers. I've been using an aquarium thermometer w/ mercury and little lines (which of course are hard to read). Which gave me a reading of 90 F. I took a pool thermometer put it in the tank and it gave me a reading of like 91. I bought a digital thermometer and it's giving me a reading of 88. So...basicly..i'm not sure what the real temp is. I'd like to think the digital is correct...BUT I'm not sure...any comments out there? Anybody else have this challenge? What do you use? Thanks...

Ed

[Carol_Roberts]

Do people thermometers go that low?

[susankay1]

I bought an infra red themometer at Radio Shack. It was about 45.00 but it gives me what I feel are acurate readings on all of my tanks. You just point it at the surface of the water and push a button, it has a digital readout. I post the temp on the outside of each tank, each day so that I can catch any fluctuations in temp right away. HTH Susan

[Mark_B]

Susan, I have the same type of thermometer and find it very acurate. I wouldn't take a farm in Georgia for it. ;D

[paniza]

hmmmm...

I do Radio Controlled racing so, I have a Raytec digital laser gun that works like a charm to checksolid surfaces.

The problem is when I put on the surface of the water, the laser goes until the glass. Now I don't know which temp I'm reading... the water of the glass.

My heater is set to 89F ... the laser gun said 80F.

80F is also what the small sticker-termometer on the outside of the glass is saying.

hmmmm.... who could be right then?

[Mark_B]

paniza, I would say your gun is correct if it matches what your sticker thermometer says. My gun also shoots the beam through the water down to the glass. Try shooting it at the water and then shoot it at the front of the tank. You should get a lower reading that way (3 to 4 degrees), Then you gun is probably correct.

Mark

[paniza]

I added a second heat, both on 89... the gun still says 80-81 in the water.

I pointed to the heater when it was on from the glass and it said 80 so, I'm sure from glass it only sees the glass temp... not the water.

now I have 500w in heater there, 75g, the room temp is about 75.

I will leave the 2 heaters there for a while... let's see if it makes any difference later on.