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erroneous readings

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erroneous readings

Postby joselito1012 » Thu Oct 04, 2012 6:26 pm

I have a Data Logger TC-08 and I´m trying to read temperatures of 1000c but the data logger reads 600c, is there something wrong with the configuration? or what could be the problem?
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Re: erroneous readings

Postby ziko » Fri Oct 05, 2012 10:21 am

Hi,

This is usually down to a number of reasons:

1)Sensor is connected to something that is applying a voltage to the probe, that is injecting a voltage into the logger that is above the Common Mode Range of the device.
2)You are using a laptop that is connected to the power supply, this could be because of a ground looping problem.

Things to try out:

If you are using a laptop try disconnecting the power supply and leave it floating.

If not then the thermocouple will need to be connected differently. How are you measuring your signal and what kind of probe are you using, i.e. the tip of the probe?

Regards
Ziko

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Re: erroneous readings

Postby ZEN2 » Mon Aug 05, 2013 3:51 pm

Hi I just thought that I would mention my problems with the TC-08 unit it has taken many months of getting the unit to work at the temperatures on our lab ovens which are electronicaly controled with lots of emf any readings above 1100 C were usless, we needed to operate and record above 1600 C (belive me we tried and tried) it just became impossible so I decided that the machine should be earthed by the chasis and case and fuly bonded, then I had all the thermocouple cable (B type) replaced with screaned cable and earthed at the machine and computer still no joy a 47mf 450V capacitor was fitted and connected from the earth to the + output of the thermocouple we then found that we had readings from both ovens up to the working temperature but with spaces in between the lines of the graph, I then fitted (just as a test) a K type thermocouple in the No 3 input and eureka after many months we have a fully working logger it has worked fully for a week I hope that this is of assistance.

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