TC-08 channels affecting each others

why channels are affecting each others? when i connect channel 8 thermocouple then readings in channel 7 is changed?

Hi,

Is the thermocouple touching anything metal?

Please try another thermcouple in channel 8.

If the problem persists, please e-mail support@picotech.com as we may need to arrange for a repair and issue a returns number.

Many thanks,

Hi,

I do have the same problem. Except of where I put on the thermocouples (where they measure the temperature), they are not touching any metal. Sometimes its working fine half an hour later it does not. Sometimes they affect each other, sometimes only one thermocouple showing the wrong temp. It occurs that all thermocouples work fine for a temperature like 40 °C, then after rising the temp to 100 °C one of them falls out.

I tried changing to new thermocouples. also switching channels. Unfortunately no improvement. It seems to be randomly.

Could there be dysfunctions due to electromagnetic radiations of an electrical motor (ventilator) nearby?
(It affects both, shielded and non-shielded wires..).

Thanks in advance for an answer!

Hi Uli,

I have responded to your e-mail support requests - below is an extract:

You can place some clear varnish on the thermocouple tips to insulate them. This can prevent any shorts from occurring. Electromagnetic sources can also have an impact on readings, please keep the USB TC-08 away from such sources of interference where possible.

Also are you using a desktop or laptop PC? If you are using a laptop PC, is it plugged into the mains power supply?

Regards,

I use a laptop PC with power supply. Unplugged it, now it works.

Thank you very much!

i was using tc-08 in large junction box (picture) , and dont know what other signal was the cause of the bad readings ... and i had also bad readings when temp was over 40 C , if real temp is about 70-80 C then tc-08 readings are jumping up and down randomly between min. temp(cold junction) 0-10 C and thermocouple real temp (70-80 C)


i have also second problem which seems ( i think)to be related electromagnetic radiations coming from AC power lines .
if i use TC-08 with laptop, all is OK ( software is running nonstop for months) , but if a use same software and same tc-08 unit with desktop PC, software is hanging after a day or so.. what could be the problem ?
i think that laptop power adapter AC-DC is better build quality and dont let electromagnetic radiations go through.

but what to do with the second problem ?
better grounding ?
uninterruptible power supply?
cable shielding?

Hi mortenx,

Is it still only channel 7 that is affected or other channels?

Have you tried swapping thermcouples between channels? Does the issue then occur on the same channel, or the new channel to which you have connected the thermocouple?

Please ensure that you are using the latest version of PicoLog (5.23.0) which can be downloaded from:

http://www.picotech.com/software.html

With regards to the PC, is the socket to which it is plugged on the same circuit as the socket to which the equipment is being powered by?

Are you using the supplied blue USB cable and what sort of USB ports are you using on the PC - are they on the front or rear?

Regards,

Hi

I used TC-08 to measure temperature but when but when I plug my laptop values ​​are distorted.
you have a solution for me ?

Thank you

Please see answer on your other post https://www.picotech.com/support/post52121.html

HI

Yesterday I recieved my ordered pico USB TC-08 data logger. I installed the program and try to perform the test by using K-Type Thermocouple (-100'C - 200'C) with universal Connector but data logger records only room temperature value(23'C - 24'C) rather than recording the working temperature ( -10'C to 50'C).

I tried all channels but got same results and in addition there is no calibration certificate provided with the purchase of the data logger .

Please advice ASAP

Regards
Sukh

Reading room temperature on an enabled channel, suggests there is no actual connection between the thermocouple and the logger. The actual reading is likely to be the cold junction temperature.

What do you mean by "universal Connector" ? Is this using a K type mini din connector ?

A picture of your setup would help.

When we ship units they are guaranteed to operate within the public specification, if you require a certificate this needs to be requested at time of purchase, and this will additionally list the table of errors for the device. There is a cost for this service.