USB 6009 thermocouple noise

[mingrid]

Hey, 

I am doing measurements with a k-type thermocoule and DAQ Usb 6009, considering using the CJC AD595, or other type.

I would love to have the program if you still have it? My email is Ingridmoe87@gmail.com

Thankful for respond;)

[VitEm]

Hello to all,

there's a very useful discussion! In the short time I'd get the same problem with T-sensing.
Kenny, I appreciate your suggestion and would like to get a possibility to test your vi.

Could I get the permission to see the post usb6008/9 and to get your vi?
Greetings,

Vitali

[ajmd]

Hello Kenny,

I'm intersted in having your program for the AD590 and USB6008.

Can you send it to me at this email : ajmd_@hotmail.com  ?

Thanks in advance,

ALEJANDRO...

[UMIK]

Hello Kenny,

I'm really interested in having your program for the AD590 and USB6009

since I am currently facing the same exact problem

I would really appreciate it if u could send it to me at this email: tamimi_11@yahoo.com

If possible any of you guys who received the vi could send it to me 

thank you in advance

Sam

[ajmd]

Hello Kenny,

I'm really interested in having your program for the AD590 and USB6008

since I am currently facing the same exact problem

I would really appreciate it if u could send it to me at this email: ajmd_85@hotmail.com

If possible any of you guys who received the vi could send it to me 

thank you in advance

Sam

[ajmd]

Hello Kenny,

I'm really interested in having your program for the AD590 and USB6008

since I am currently facing the same exact problem

I would really appreciate it if u could send it to me at this email: ajmd_85@hotmail.com

If possible any of you guys who received the vi could send it to me 

thank you in advance

Sam

[VitEm]

Hello to all,

I' wondoring if Kenny send anybody last posters his vi or invitation to the closed discussion.

Could anybody else help me to read this topic or send the desired vi?

I'd appreciate your help!

[Gachovska]

Hi,

I need help. I want to measure the temperature of an IGBT during the switching,

I want to use 3 thermocouple type K and I have software DAQmx 9.5 and Labview2009, and the hardware are PCIe-6351, SCB-68.

The IGBT works with frequency 10 000Hz, Then the sampling rate that I will want to use should be 1000,000 (1M).

When I connect the thermocouple and start measuring using an example program from Labview I can see so big noise (-20 to +20) although the IGBT is not working.

Could you please advice me, so I can make my experiment.

Thank you,

Tanya

[johnsold]

Tanya,

Your question has nothing to do with the USB-6009 although it is otherwise related to the topic of this thread. It might have been better to start a new thread and refer to this one if you have tried things mentioned here.

1. What kind of signal conditioning are you using?  At 150 degrees C a type K thermocouple generates 6.1 mV.  While the devices you are using can, in principle, measure the thermocouples directly, it is likely that you will have some problems. The absolute accuracy is specified as about 10 times larger than the resolution, and that is based on averaging 10000 samples. An isolated preamplifier mounted close to the thermocouple might give better results.

2. The "noise" you are seeing, is the +/- 20 in degrees, LSBs, uV, or some other units? Is it random or periodic (power line frequency)?

3. What style of thermocouple are you using? Is it connected to the case of the IGBT?  What kind of test circuit will you be using?

4. Will the DAQ system be measuring anything else in addition to the temperature?

Lynn

[Gachovska]

Hi Linn,
Thank you for your quick respond.

I need to measure the case temperature of the IGBT. I will measure Vce   and Ic of the IGBT using an oscilloscope. The first pulse will trigger the measurement of the temperature.
I have not tried yet when the IGBT is working, because when it is not the temperature should me approximately 25 C and the the output shows 5-50 C.

Tanya

[johnsold]

Tanya,

From a table of Type K values it appears that you are seeing about 1 mV of noise on a 1 mV signal.

Is this variation random or periodic?

When you see this noise, is the IGBT case grounded or floating?

Lynn