Wrong Measurement with Max31855 about picoreflow HOT 6 CLOSED

You may would like have a look at:

http://www.eevblog.com/forum/projects/max31855-temperature-error/30/

https://translate.google.pt/translate?sl=pt&tl=en&js=y&prev=_t&hl=pt-PT&ie=UTF-8&u=http%3A%2F%2Flusorobotica.com%2Findex.php%3Ftopic%3D7908.msg88928%23msg88928&edit-text=

There are some official faulty batch being selling by major component dealers (eg: mouser, digikey..etc)

from picoreflow.

Testing with Calibrator :

Calibrator : 25°C
picoReflow: 22°C

Calibrator : 100°C
picoReflow: 76°C

Calibrator : 225°C
picoReflow: 163°C

Calibrator : 350°C
picoReflow: 252°C

from picoreflow.

Yes it looks like it is a Max31855 faulty batch. I had the same issues while trying to make a reflow oven. In my experience the different was not so big as yours. But the behavior was the same: the more the temperature increases, the more the difference.

from picoreflow.

Dooooh ! Yes its a faulty Batch ....

2 of the Max31855 I tested where from an order last Year (Mouser). Datecode -> 1352A2 - 23AL
The third Max is from this Week from Conrad Electronic, but has the same Date Code :-(

from picoreflow.

The maxim IC knows it, probably Mouser/Digikey knows it too.. and still sell it that way :|

from picoreflow.

Meh, that's a shame and always happens when you need it the least :/ The modules we got from watterott.com have not had any issues, I've verified the metrics against a reference thermometer during dev/testing. But I had the same issue with a DS1820. As it seems to have been a HW problem, I'll close the ticket if no one raises any objections.

from picoreflow.