6016 cold junction setup

[randyram]

I am trying to use the 6016 to measure temperature in a chamber. I am aware that there is no built-in compensation network in there. So, my reading is all over.

I would like to use another thermacouple outside of the chamber as reference for the thermacouple that is inside of the chamer. I understand that the reference might drift a bit depending on the room temp, but at least it will be better than not using it.

How can I implement this? I using the DAQmx Assistant to do this. And at the bottom, where I set up the CJC, I choose channel but what do I type in there? 14 since reference channel is 14. I keep getting message saying that where is no such channel.

Or is there a better way to it? Can I place a know voltage in one of the ports to create a reference. Again, how to I tell the DAQ Assistance to use this as reference.

[hrh1818]

On Apr 21, 2:10 pm, randyram <x...@no.email> wrote:
> I am trying to use the 6016 to measure temperature in a chamber. I am aware that there is no built-in compensation network in there. So, my reading is all over.
> I would like to use another thermacouple outside of the chamber as reference for the thermacouple that is inside of the chamer. I understand that the reference might drift a bit depending on the room temp, but at least it will be better than not using it.
> &nbsp;
> How can I implement this? I using the DAQmx Assistant to do this. And at the bottom, where I set up the CJC, I choose channel but what do I type in there? 14 since reference channel is&nbsp;14. I keep getting message saying that where is no such channel.
> &nbsp;
> Or is there a better way to it? Can I place a know voltage in one of the ports to create a reference. Again, how to I tell the DAQ Assistance to use this as&nbsp;reference.
> &nbsp;
> &nbsp;

With you 6016 located outside of your chamber and your thermocouple
located inside your chamber connecting a second thermocouple located
outside the chamber to your 6016 will not gain any thing. The output
from a thermocouple is proportional to the difference in temperature
of the two junctions. In the setup you propose the two junctions will
be at the same temperature and will produce approximately zero output
voltage.

If your room temperature variation is relatively small you could
insulate the terminals of your 6016. The object of the insulation is
to dampen short term temperature excursions. Another possibility is
to use a temperature controlled oven to maintain your reference
junction at a constant temperature. Frequently these ovens are
operated at 150 degree Fahrenheit. A third possibility is a self
powered reference junction. See.
http://www.omega.com/ppt/pptsc.asp?ref=LXCJ&Nav=temk03

Howard

[hrh1818]

On Apr 21, 7:27 pm, hrh1818 <hr...@att.net> wrote:
> On Apr 21, 2:10 pm, randyram <x...@no.email> wrote:
>
> > I am trying to use the 6016 to measure temperature in a chamber. I am aware that there is no built-in compensation network in there. So, my reading is all over.
> > I would like to use another thermacouple outside of the chamber as reference for the thermacouple that is inside of the chamer. I understand that the reference might drift a bit depending on the room temp, but at least it will be better than not using it.
> > &nbsp;
> > How can I implement this? I using the DAQmx Assistant to do this. And at the bottom, where I set up the CJC, I choose channel but what do I type in there? 14 since reference channel is&nbsp;14. I keep getting message saying that where is no such channel.
> > &nbsp;
> > Or is there a better way to it? Can I place a know voltage in one of the ports to create a reference. Again, how to I tell the DAQ Assistance to use this as&nbsp;reference.
> > &nbsp;
> > &nbsp;
>
> With you 6016 located outside of your chamber and your thermocouple
> located inside your chamber connecting a second thermocouple located
> outside the chamber to your 6016 will not gain any thing. The output
> from a thermocouple is proportional to the difference in temperature
> of the two junctions. In the setup you propose the two junctions will
> be at the same temperature and will produce approximately zero output
> voltage.
>
> If your room temperature variation is relatively small you could
> insulate the terminals of your 6016. The object of the insulation is
> to dampen short term temperature excursions. Another possibility is
> to use a temperature controlled oven to maintain your reference
> junction at a constant temperature. Frequently these ovens are
> operated at 150 degree Fahrenheit. A third possibility is a self
> powered reference junction. See.http://www.omega.com/ppt/pptsc.asp?ref=LXCJ&Nav=temk03
>
> Howard

Another possibility is to use a semiconductor temperature sensor to
measure the temperature of your cold junction and then use the output
of the sensor to compensate your thermocouple readings for room
temperature variations. See:
http://www.temperatures.com/semivendors.html for a list o vendors who
manufacture semiconductor temperature sensors.

Howard

[randyram]

I am looking at the part that you suggested from Omega.

Doesn't really really show how it works or how I would connect it.

Have you use them before?

let me ask them for more details on it.

Thanks

[hrh1818]

On Apr 22, 11:10 am, randyram <x...@no.email> wrote:
> I am looking at the part that you suggested from Omega.
> Doesn't really really show how it works or how I would connect it.
> Have you use them before?
> let me ask them for more details on it.
> &nbsp;
> Thanks

I have never used this device. If you click on Specs next to the
Adobe Acrobat symbol you can get a little more information. Like it
uses solid state circuitry, it as leads you connect to, the color code
for the leads, and the thermocouple leads are solid wire. If you use
it I recommend you use thermocouple rated connectors for making
connections to your thermocouple. The biggest drawback for the LXCJ-
(*) is if you have more than one thermocouple you need one LXCJ-(*)
for for each thermocouple.

Howard