Thermometer is off

So last brew session my friend dropped the thermometer into the MLT right after dough in. We fished it out and continued to use it thru the brew day.

Last week i decided to buy another since water got inside the other one and it might be off now. I compared the 2 during the boil last weekend and the new one is 10 degrees higher than the old. I tested a smaller meat thermometer against them, and it gave me the same reading as the old thermometer. Then i tested all 3 against a candy thermometer, which read 5 degrees lower than the new thermometer and 5 degrees higher than the other 2.

What gives? How do i get a thermometer that gives correct temps? Do i need to go digital?

 

I went through the same thing and eventually got a Thermapen.

Even cheap digitals were all over the place for me.

 

+1 on the thermapen.

King Aurthur Flour always seems to have a 10% off coupon going.
http://www.retailmenot.com/view/kingarthurflour.com

Here's my original thread on the deal.
http://www.homebrewtalk.com/f11/awesome-thermapen-deal-kingarthurflour-com-155658/

 

Thanks for the info guys!

 

Thermapen is great. Used mine for the first time on my last brew, tested it in boiling water and it was spot on. I used it to calibrate all my el cheapo dial meat thermometers.

 

I have a similar problem with my thermometers and really want to hit my temps. I know that the Thermapen is great, but does anyone know of anything cheaper that is also good? I've recently moved to all grain and kegging, so money is a little tight now.

How do Type K thermocouples with a mutli-meter compare?

 

I've been doing some reading because i don't really want to spend $100 on a thermometer either, rather use that for a new mill. But it seems that a lot of ppl use the long glass lab thermometers and they are supposed to be very accurate. I saw them at my LHBS on the bottom shelf for 8 bucks i think, but i ended up going with one of the long probe types that come with turkey fryers for $15

I did read some positive reviews for the thermocouples and multi-meter if your has a temp setting.