Do I Have 2 Have A Thing That Tells You The Temp In A Tank

[OldMan47]

I must agree with you Bignose. An alcohol thermometer is easy to make and calibrate, hence the low price. If you have any doubt as to accuracy, try checking all the thermometers hanging in the same area of the LFS. They had better all be within about 1 degree of each other, which confirms they are all giving the same information. I have had some decent luck with a heater setting only on one brand of heater and even so would still trust the thermometer first.

 

[thefubar]

Thanks for a good point. I think sometimes there is a natural assumption that because its cost you more, its a better piece of kit. Which isn't always the case. Maintaining a constant and stable temperature is often taken for granted by newcomers (me included) but with the influence of ambient room temp, heater and proximity to windows and radiators it can be a tricky task and lead to unexpected problems.

I lost quite a number of cherry shrimp in the summer and this is *possibly* due to varying temps during the summer heatwave.

 

[raptorrex]

Do you deduce that it is the £1 thermometer or the £30 heater which is incorrect in reading the temperature of the tank?

Actually, I do more strongly suspect that it is the heater.  Simply because it is much, much easier to make an accurate thermometer than an accurate heater.  The properties of the alcohol mixture in the thermometer is very, very well known and it is only a few variables in the manufacture -- get the correct volume in the tube, and get the tube aligned correctly to the markings.  To make a heater, the electrical resistance of the heating element has to be exactly right, the thermal resistance of the sheath material has to be exactly right, the on-off switch has to be calibrated right, the knob has to be lined up.  Considering how cheaply they do make these heaters, there is no way that the quality control is very tight on these.  I could very well be wrong, but that is my suspicion.

this falls in with my experience too. Heaters and, cheap, digital thermometers. have far more variance, in accuracy, that any spirit thermometer. I made the mistake of purchasing an Calibrate-able  thermometer, from Fluke, costing a fortune. all it ever did was, confirm that the £1 spirit item. was more than accurate enough for, virtually, any task. the Fluke sits in the draw now. 

 

[fluvial]

According to the reading on both my thermometers the temperature in the tank is a steady 24C,
although the heater is set at 28C.
Obviously the heater is working correctly, maintaining a steady temp - but the accuracy of the reading comes from the thermometers.

I would not trust the setting on the heater if the thermometers are giving a different reading