Since I knew I was going to be at home this week, assisting my bride after her back fusion, I ordered last week so it would be here today for testing.
Here is a link to the specs on the Extech TM55: http://www.smokingmeatforums.com/t/237568/extech-tm55-anyone-tried-it
So, I got the thermometer this morning and set about checking the accuracy.
It came in a big box, but the actual package for the thermometer was just so so.
After opening it up, I removed the battery tab, and powered it up. To power up, you simply fold out the probe, kind of like another thermo out there.
After opening the probe, the temperature read pretty close to what the temp was in my kitchen, warm since I was cooking at the time.
I filled a plastic cup with ice, sat the probe into the ice, and waited for the temp to stabilize. It took about 6 seconds by my count. The temp stabilized at 31.1 degrees. Not too bad.
I pulled the probe out of the ice, let it get back to room temp, and then put the probe into boiling water. 210.5 degrees was shown in about 6 seconds. That's basically right on the money for my location.
So, thus far, I'm impressed with the response time, recovery time, and accuracy. The proof will be in the meat testing. That will have to wait, raining here today. But it'll happen this week for sure!