Variation issues _ Temperature monitoring

[Jane]

Hi,

We used the TT-T-30-SLE-25 coupled with MCC USB-TEMP and TC Series: Temperature and Voltage Measurement USB DAQ Devices to measure temperature continuously. However, the temperature values were about ~2-3C lower than that measured by a mercury thermometer. 

Could you please help provide any solutions to eliminate the variation?

Thanks,

Jane

[Fausto]

Hello @Jane.

Please describe the environment conditions for the USB-TC. 

What is the temperature range to be measured?

Relocate the USB-TC device if there are any EMF generating equipment (i.e. pumps, motors) nearby.

The thermocouple ends/tips should not be in direct contact with a metal surface and should be covered with an epoxy or thin film.

What is the length of each thermcouple?

The number of channels enabled in software should match the number of thermocouples connected to the device; starting with input CH0.

Allow a 30 minute warm up time before acquiring data.

The USB-TC is calibrated at the factory.  If the device has not been calibrated in the past year, run InstaCal's calibration option.

Below is the accuracy table of the USB-TC according to the sensor type.  The thermocouple itself has its own error specification from the manufacturer.

 

Regards,

Fausto