Thermometer

[braailus]

Hi guys, I was just wondering what you use to keep an eye on temperatures. I bought 3 digital devices that are identical except for the temp readings. One is totally different from the others, as far as rate of change as well as actual temperature. It is obviously wrong so I do not use it. The other two are fairly close in their readings so I assumed that they were correct. That is until I installed my STC1000 in a freezer. I decided to use one of the 2 good thermometers just as a calibration check. The two probes are both dangling in the freezer next to each other so the readings should be identical. Needless to say, they differ between one and two degrees over time. The range is 17 dC to 18,5 dC on the one and 18 dC to 20 dC on the other. Is this close enough?

I would just like to know what the actual temperature is but what do I get that I can use as a reference? Are the glass thermometers you buy at the chemist truly accurate? Somehow I doubt that they would all be 100% accurate. Especially at 18 degrees because as a human your body would never be at that temp.

Your input please.

[bquiggerz]

Boiling water and ice are best for calibration as there are almost true readings. That is of cause altitude/pressure sensitive but foot the most part this will give you an accuracy that would be considered fine to work with. Hope that helps.

Ben.

Edit: best temperatures to test*

[LeeH]

Ask Santa for a Thermopen. They come with a calibration cert so can be used as a datum against your cheaper ones, STC, PID controllers etc.

[braailus]

Thanks, I will investigate

[Pinto]

Ask Santa for a Thermopen. They come with a calibration cert so can be used as a datum against your cheaper ones, STC, PID controllers etc.

I have a little cheat myself - as an electrician my Test equipment is calibrated every year and the boss picks up the bill. Shame my multimeter I use also comes with a thermocouple so that gets done too

I then calibrate everything else against that.

[LeeH]

That's a great idea. I can do that too, I'll order myself a new meter on the next job!

[LeeH]

Have you asked they actually calibrate the temp? I think MTI do ours.

[Pinto]

Yeah, the Test meter and multimeter get their own CoC's and temp is included on the one for the multimeter they test all the available functions so you have to make sure the thermocouple is in the bag when it goes away tho

Ours go away via Eyre & Ellistons so its whichever service they use at time.

[braailus]

I assume you guys use Fluke?. Unfortunately that is not an option for me.

[brewnaboinne]

The ordinary glass thermometers like Youngs seem accurate but if you want real precision you could try a laboratory suppliers for something like the one's Zeals make

[Matt in Birdham]

Ask Santa for a Thermopen. They come with a calibration cert so can be used as a datum against your cheaper ones, STC, PID controllers etc.

Seconded - awesome bits of kit, the speed at which they work is great, as is the accuracy. Just did a calibration test on mine a few weeks back and was still within 0.2C after 4 years of hard use (calibrated with both boiling and freezing temps). Well worth the dosh IMO, also incredibly useful for general cooking duties.

[f00b4r]

Eti have an outlet store on eBay which are really cheap with full guarantee, even cheaper if you can combine with one of the eBay 20% off everything days

[Pinto]

I assume you guys use Fluke?. Unfortunately that is not an option for me.

Nope, Kewtech. Dont get blinded by the big brand names as they are rarely, if ever, worth the premium price they think their gear is worth (unless you're talking lab grade analytical stuff - and those cost thousands.....)

http://www.screwfix.com/p/kewtech-kt116 ... robe/94916

(Just noticed that the Kewtech above comes with a CoC cert so it's calibrated for the 1st year anyway)

[Dennis King]

I used a Thermopen but they need care they are not waterproof

[f00b4r]

I used a Thermopen but they need care they are not waterproof

They just brought of a newer version that is IP66/67 rated (unfortunately just after I picked up the older version).