I have stumbled upon a problem with my TC-08 datalogger. I usually record heating curves of different metals in a 600 °C hot furnace with type-K thermocouples. This week, I tried to differentiate the data to get the heating rates and found that the TC-08 obviously suffers a timing problem when recording data: when I display the calculated heating rates over time in a graph, there are two separated curves shown!
It seems that, at a recording rate of 4Hz (250 ms per measurement), the heating rates calculated from the recorded temperature data with simple difference quotients alternate in pairs, i.e. there are always two values below followed by two values above the what I suppose is the correct, actual heating rate. It seems that temperature values are not recorded every 250 ms, but more like every 200 ms for two times, followed by two measurements with a 300 ms gap. Then the cycle starts again with two 200 ms measurements...
Here's an image to get you an idea how the result looks like:
I am pretty sure that this is faulty behaviour of the TC-08, as I have done this with other data loggers and the results were fine. Could it be that the TC-08 can't actually handle the "high" sample rate? Is there anything one can do about this? Has anybody else experienced this?
Thank's for your help!