Problem with USB-1616HS thermocouple

[LouisR]

Hello, my question is about the USB-1616HS. I mounted 2 thermocouples on it. When I take the same temperature at a same point multiple times (I am using TracerDAQ), the temperature detected is always different than the previous one and it is not the expected temperature (it was supposed to be 115 degrees in both graphs below).

I wanted to know if there is something I am not doing the right way as the temperature should be the same between every measurement. 

Thank you for your answer,

Louis R.

 

[Fausto]

Hello @LouisR.

What is the age of your USB-1616HS module?

Have you acquired correct temperature readings previously, with or without using TracerDAQ, and with those specific thermocouples?

Have you tested other thermocouples with the USB-1616HS module?

Are the ends of the thermocouples connected directly to a surface or in the air?

If you exit TracerDAQ and open InstaCal to take some measurements, are the readings correct?

Regards,

Fausto

 

[LouisR]

I don't know the exact age of my USB-1616HS, the serial number is 394943 (someone told me it has been at least 3 years)

I never worked on this module or these thermocouples before so I have never acquired the correct temperature using it.

I currently only have these 2 thermocouples so I didn't try with another one. 

The ends are connected directly to a surface. 

And about Instacal, I used it to calibrate the device before utilization but the results still aren't accurate.

Thanks for your help,

Louis R.

[Fausto]

Hello @LouisR.

Your serial number dates back to May 2019.

Your image of the USB-1616HS and thermocouple show a thin film tape at the thermocouple's tip.  Please confirm that both thermocouple tips are not in direct contact with a metal surface.  Also, please verify that the thermocouple leads are secured at the screw terminals.  Reference Figure 1 on page 9 of the USB-1616HS User's Guide for a thermocouple connection.  Your thermocouple connections should begin with analog input channel 0 and you should not leave an open channel between thermocouple connections.

https://www.mccdaq.com/pdfs/manuals/USB-1616HS.pdf

In InstaCal, verify that the Input Mode is set to 'Differential (8ch)'.  

 

Configure the thermocouple channels on the next tab.

 

 

What are the lengths of your thermocouples?

Additional 'tips for making accurate temperature measurements' are listed on pages 19-20 of the USB-1616HS User's Guide.

If you continue to have an issue with your temperature measurements, then we can take this offline to discuss a RMA for sending the device in to be tested/repaired. 

Regards,

Fausto

[LouisR]

Hello, 

I tried again, using the advices you gave me and the tips in the notice. The temperature still is not accurate. 

The lengths of the thermocouple is approximately 2 meters.

Regards,

Louis R.

[Fausto]

This post will be addressed over private message as a possible repair.