Load Cell and 1746-NR4

Mark Buskell

Member
Join Date
Sep 2003
Location
Florida
Posts
892
Does anyone know if it is possible to use a Thermocouple/ mV
Analog Input Module 1746-NR4 to measure data from a load cell.
The 3 load cells that we are using are Paralleled together to give an output of 6 millivolts at max. Since the NR4 can measure up to 50mv,
I was wondering if it is all possible this way.

I will more than likely use an amplifier and then convert the signal to 0 to 10 volts.

Can anyone suggest a amplifier? Cleveland-Kidder makes one called a Ultra that mounts on a din-rail.

Also these load cells require a 10V input, can anyone recommend a 10V power supply. I think 12V power supply probably is to high.

FYI: The customer assured us that each load cell outputs a 0-10 vdc so we ordered a 1746-NI4 module. I was going to sum the inputs, divide by 3 and then scale the data. After looking them over today, we discovered that its only a millivolt output with no amplifier and now at the the last minute, we are scurrying to order amps and power supplys tomorrow.
 
At my facility we have a LOT of load cells, and always use a "summing" box and interface from the vendor. We mostly use metler-toledo and the interface can be configured(using option cards) for what ever you need. 0-10 volt, 4-20, serial, ethernet, RIO etc.....
 
M-Systems, Sensotec, and others have strain guage amplifiers that will provide exctation voltage for the load cells and output 4-20 mA or 0-10 VDC. They are usually 24 VDC powered.
 
When 10V is needed I simply use two 5V power supplies
with outputs in series. 12V power supplies even if they can be adjusted down to 10V are poor choice
because one day someone might replace it or crank it up to "correct" voltage.
 
Hellow everybody

I facing asame problem with AD TC/mV card I want to save the coverter
and to be more accurate mV card have 16 bit resolution, analog input have 12 bit resolution.

What I have been told is to supply the load cell from different source then the card power supply.
That mean one power supply for the load cell and one for the card.
The reason is to avoid noises problem and to keep the resistor bridge balanced.

I did not try it yet I wating to the stuff from AD.

Please let me know if you find something new.
 
Update

We ended up ordering a amplifier from Cleveland-Kidder and a Sola power supply. They are being sent Saturday express and better arrive this morning.

I am still curious about using a 1746-NR4 module but right now do not have the card with me or the luxury of time to test it.

Thanks for all of the suggestions, I will look into them.
 
A customer of mine did this a couple of years ago with quite a few load cells in a plasctic production plant. Worked quite well. If you want I can get you details.

(8{)} ( .)

Yosi
 

Similar Topics

Whats the chance of using a 1746-nt4 (millivolt input) to a regular loadcell (millivolt Output so to speak) any ideas? I've got one of each but...
Replies
1
Views
1,532
Good Afternoon, I’m limited with a skilled maintenance staff to design and build Load Cell , Rollers , etc. for conveyor sections . Do...
Replies
11
Views
629
Good Afternoon , Does Rockwell Automation have an Input Card , maybe in the 1734 series , or CompactLogix series that will receive signals...
Replies
15
Views
774
Can someone recommend an Intrinsically safe barrier that can be used with an "ANALOG" load cell on a weigh scale? Load Cell is rated to be in a...
Replies
4
Views
1,343
Hello All, I have two bags of two different types of peanuts hanging on a load cell above two separate feeders. I am using Studio 5000 and would...
Replies
45
Views
8,773
Back
Top Bottom