PDA

View Full Version : Mercury or digital thermometer



jojo
25th Jul 2008, 07:24 PM
Hi
I hope this is not a silly question but I have different reading from a mercury thermometer ($1.50) and digital thermometer with a wire probe($9.50). Both are new, the mercury read 27C and the digital read 25.4C that 2C different. Both equipments place near to each other in the tank. Can someone help me on this? or anyone can recommend a reliable mercury thermometer. thanks:undecided

Rabbit
26th Jul 2008, 11:09 AM
yo bro, here is an idea. i use to work in fnb, this abstract is taken from a website that helps calibrate a food probe thermometer.

How to you know a thermometer is accurate? The answer is to check it in ice water. Water freezes at 32 F.; therefore, a glass of ice water will be very close to 32F. By setting the thermometer in the ice water for a few minutes, you can find out if the thermometer is accurate if it correctly reads 32F.

sorry i cant cite my soruces coz it say new members cannot use URL tags. thank god my lecturer is not here to penalize me on failure to cite my sources.

do that for both your thermometer and u will get an answer :) (well u dont really need to do it to both, but im just idiot proofing it for u) hee hee

jojo
27th Jul 2008, 02:12 PM
Hi rabbit
Did that and both went down to 0C. The mercury thermometer went even below the scale 0 :p. Just hope someone can recommend a better brand mercury:cry:

retardo
27th Jul 2008, 02:42 PM
Sounds like your thermometer needs to be calibrated as well. The best thing to do at least as far as the digital thermometer is concerned is to allow it to sit for a few minutes before turning it on.

Rabbit
27th Jul 2008, 03:22 PM
Hi rabbit
Did that and both went down to 0C. The mercury thermometer went even below the scale 0 :p. Just hope someone can recommend a better brand mercury:cry:

dude congrats u manage to discover h20 in liquid state below 0 degrees~!

either tat or your merc thermometer is faulty.

nonetheless, its only $1.50, i got mine for 2bucks.

so go with the readings on the digital one.

silane
27th Jul 2008, 06:45 PM
Lot of aquarium use thermometer is not accurate, either glass or digital. I have yet to find something that work well. If you have some known good make and model, do share.

The problem is with some shrimps, higher limit of temperature is critical and can often hit and prolong hit temperature is alway a problem if not taken care off or a themometer fail to give an accurate reading.