Thermocouple and ML1100

I am in a bit of a quandry and have little experience with Temp sensors.
The techs installed a ML1100 to read flow from a heads up unit. I have that going to a IF4(4-20 setup) card and all is good there. They now want to add 4 thermocouples to this unit per the Maintenance Manager. None of this was thought out, they just did it. I am not left to integrate this into the HMI.

They have selected this thermocouple: http://www.omega.com/pptst/SA2.html
This is a Type T thermocouple and they have already run the cabling. They are wanting to read some temps from two Hot Water Generators for a specific small area.

What is the proper card I need to get for this application?
1762-IR4 or a 1762-IT4?

I checked Omega's site and they have some transceivers I can get to turn this into a 4-20mA signal or do I just use the RTD card? What is the best option and the scaling for this application type?

I apologize for any ignorance on my part beforehand. Any help help or any direction you can point me in would be greatly appreciated.

Unless you can return the analogue card it may be cheaper to buy a converter
Type T to 4~20 mA the proper card would be better but the cost could be high
see how you go

iant said:

Unless you can return the analogue card it may be cheaper to buy a converter
Type T to 4~20 mA the proper card would be better but the cost could be high
see how you go

Click to expand...

I appreciate your feedback iant. The up side to them just installing this stuff, all I got was a copy of the invoice so I could look up parts and whatnot, is that a card has not been ordered. The original IF4 card is fully filled with analog from previously installed flow meters.

I am just not in the know of which card to order to accomodate these new 4 thermocouples.

Cool I dont have the details infront of me - Someone will answer shortly

I assume that a type'T' thermocouple needs to have a card that will accept it I am guessing the 1T4 might be the right one see how u go

If you want to connect your thermocouples directly then the 1762-IT4 ( Thermocouple input card) is the one you need.
Or get transducers to convert the thermocouples to 4-20ma as mentioned above and get the 1762-IF4 card.

Gents,

Thanks for the information and the help. You don't know how much it is appreciated. What kind of scaling what I would I use or rather what is the source voltage? The PDF does not specifically indicate it.

Aeroman said:

Gents,

Thanks for the information and the help. You don't know how much it is appreciated. What kind of scaling what I would I use or rather what is the source voltage? The PDF does not specifically indicate it.

Click to expand...

What PDF? Which card are you planning to use?

Look up spectrum Controls they make a universal analog input card that is great. I have used them several times.

It HAS to be a Friday. I see what I need to do. Again, I appreciate all the feedback.

>and they have already run the cabling.

I assume that this is refers to the cabling between where the thermocouple installs and the input card.

Is it thermocouple extension wire? the same type as the thermocouple?

A thermocouple REQUIRES thermocouple extension wire. No exceptions. A thermocouple signal will produce considerable error when connected with copper wire.

If the cable is in already and it's copper wire, and it's a big deal to keep the copper wire or to not change to the correct type thermocouple extension wire, then you should use a thermocouple transmitter local to where the thermocouple is located and send its 4-20mA signal back on copper wire.

Dan, you are right on the money there. If it is copper, put a signal transducer where the thermocouple wire ends.

Hmmm. You're looking at a $grand as I see it. 4-20mA 4 channel card, plus 4 channels thermocouple transducer, or A/B T/C card with thermocouple extension wire and proper terminations throughout or, this little field I/O which should be a nice exercise in Comms for around $900 by the time you get a box for it if necessary.

http://www.automationdirect.com/adc...or_I-z-O_Network_Interface_Modules/T1H-EBC100
http://www.automationdirect.com/adc...z-O/Terminator_I-z-O_Analog_Modules/T1F-14THM

14 channels for the price of four...