Temperature acquisition and logging using thermocouple

[maxidivine]

Good day,

Please I need an assitance on how to go about using Labview to acquire temperature from a type K thermocouple, with signal conditioning and use a file storage to log data. It should have graphical output for analysis.

Thank you so much. 

[J POWER]

Hi,

There are express Vi int the express pallet within the block diagram, these allow quick data aqusition

They are found in the: Express >> input >> DAQ assistan, then folow the setting and select the relevent options. then add the graphica indicator in the data output.

This will show your temp.then get a 'write to measurement file' from the Express >> output >> write to meas.

Then wire the data out from the DAQ assistant to the data input on the write to. And follow the set up instructions and file save location etc.

this will run once so you need to add a while loop around the functions and wire in the error and a stop to control the loop

Regards

[maxidivine]

Thanks a lot. I am new to LabView 8.5 and so if I run into any troubles, I'll be back. Thanks

[J POWER]

Hi,

Have you thought about having any trainign with LabVIEW?

National Instruments provide three levels of training from begining basics to advanced, i new to the company and have sat the basics course and the intermediate course, both of which are very useful. They show you the full range and capability of LabVIEW, and are comitted to helping.

If you are interested and would like to get some more information please call the office. 01635 523 545

Regards

[maxidivine]

Jordan Power, thanks a lot for your wonderful advice and assistance so far. You have certainly inspired me. I have till Friday to complete the acquisition program and so I may not have time just yet for the intermediate course. Probably in two weeks, I will.

Meanwhile, after desiging the circuit, I have made progress on the program as per specifications as follows:

-graphical output and an alarm for room temperatures outside the (20C-30C) range.

-file storage of the mean value of the temperature for data logging purposes.

However I encountered the following challenges:

- the min temperature displayed on the front panel was about 0.06C (for an experiment performed at room temp I feel this was due to transients) there was no problem with max and mean temps displayed however

-Inability to put a loop around the "write to file option" alone, so that the data logging occurs after every 20 seconds and the process is independednt on every other process.

I have attached a file of the program. Please help on this one.

Thanks a lot. 

[J POWER]

Hi,

       For the data logging you could try to export data to a excel file.

This would allow you to view the data and filter the data points in there.

You can also read from the excel file so you will still be able to reuse the infomation in LabVIEW.

when i run the VI on my machine I get veyr large values what are u trying to do with the signal condition VI?

Regards

[maxidivine]

Basically, the thermocouple measures the room temperature. The VI acquires the instantaneous temperature data and does a min, max and mean value over a certain time. The temperature data logged basically should be the average value of temperature for say, every 20 seconds. This is to be logged in excel. Thats basically it. The main challenge for me has been having to do a good time delay so that the average temperature every 20 seconds in logged in the excel, and read from excel, on demand.

Thanks a great deal.