Digital Thermometer
 

Well, I sure liked my digital thermometer but I have discovered a problem. It is out by 4 degrees +. For some reason I just decided to buy myself an old school thermometer. I lowered the temp to what I thought was 78 from 82 (which would have been 86 (more on a hot day) but the new meter says I'm still 82. OMG

I lowered the heat and now the new meter is reading 78!
Geeeee, I wonder why my tank was green :eek:

You'd think I would have clued in earlier!

Food for thought!

Ive always thought of buying a backup thermometer but never really got around to it as my tank always looks fine. Now I am curious to see if my Digital Stick-on Thermometer is out as well. :confused:

From my experience, almost all of my old analog thermometers that I've used in the past were reading too low because some of the liquid ("mercury" or alchohol or whatever the liquid is) got trapped at the top of the thermometer so the actual temp would be higher than the readings showed.

I have 2 digital battery-operated thermometers and a stick-on (analog) in my office and all 3 show about the same temp even though it feels cooler than they show. They all say that my office is 26C. Its weird but I assume the 3 thermometers are right.

reply
 

I use a old school alcohole thermomter and it has a 1mm air gap in the liquid. I just lower my reading by 1 degree to compensate, it just goes to show how cheep those things are.

For mercury and alcohol thermometers, you can easily join the columns. Try first holding vertical and gently tap bulb until joined. If that does work slowly warm until the fluid just below the break goes into the expansion chamber then let gradually cool in the vertical. The alcohol most always stays together, some times the mercury will breaker again in the same spot.

or buy a new one for 1.99.