Help for load cell

[Ario]

Dear Masters
I have bought a load cell(made in china) without any datasheet and this is the
only data that i could get from seller in a very small piece of paper!

1-capacity(kg): 60
2-Thread Type : M
3-Calibration Mode :Compression
4-Sensitivity: 2+-0.2mv/v
5-Input Impedance : 415+-15 ohms
6-Output Impedance : 350+-3 ohms
7-Insulation Resistance >2 G Ohms
8-Test excitation : 10v DC
9-Zero Balance <+-3% of cn/k
10-Total Error : 0.020% of cn/k
11-Non Repeatibility : 0.010% of cn/k
12-Zero Return : 0.023% of cn/k
13-Temperature effect on zero : 0.0035% /C
14-Temperature effect on Sensitivity : 0.0014% /C
15-Compensated Temperature : -10~+40 C
16-Safe Temperature : -25~70 C
-------------------------------------------
Cable Color Code
Red=+Excitation
Green=+signal
White=-Excitition
Blue=-signal
-------------------------------------------

Can anybody help me to find out this specifications?Is there any complete project for load cell interfacing with a micro controller such as avr or pic or ...?

[sfiga69]

look this:
 
http://www.cirrus.com/en/pubs/appNote/an36.pdf
 
http://www.aeroconsystems.com/electronics/load_cell_primer.pdf
http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1155,D6637
http://www.cirrus.com/en/pubs/appNote/an31.pdf
 
Bye

[vayupak_01]

Hi sfiga, Are you have any schmatic for some digital scale?

[dekor]

Hi,
do you have any schematic for a device to check load cell?
Please share with us .
Thanks,
dekor

[FriskyFerret]

>Can anybody help me to find out this specifications?

You already have all the specifications. You just have no idea what to do with them. You need to understand load cells, how to excite and signal condition them, and how to apply them mechanically. Time to learn.

[kareemsa]

Hello Ario,

What you are having is the exact specification of the loadcell,
what i understand is that you don't how to check.
I shall help you check the loadcell.
Do exactly as mentioned.

Apply 5 Volts DC between, red & white wire of the loadcell cable

                         Red=+Excitation & White=-Excitition

Connect a multimeter in the millivolts range between, Green & Blue wire of the loadcell cable

                          Green=+signal & Blue=-signal

Now apply the load on to the loadcell approximately 10Kgs, the multimeter should read approximately 1.66millivolts.
Then place 20Kgs load the multimeter should read approximately 3.33millivolts.
And now place 30Kgs load the multimeter should read approximately 5.00millivolts.
The readings on the multimeter should be linear as you are increasing the load linearly.
Remember the output is always in millivolts.

Since you are exciting the loadcell with 5VDC and applying only 10Kgs load on to the loadcell you will get only 1.66millivolts the output .

The calculation is as under

Sensitivity is 2mV/V, Capacity is 60Kgs, & the Excitation is 10VDC

    Sensitivity X Excitation /Capacity X applied load = millivolts output.
    i.e.  Ex1 :  2x10/60X10Kgs = millivolts output
    i.e.  Ex2 :  2x 5/60X10Kgs =  1.66millivolts

Hope this is clear to you in case of further ambiguity post your request on the forum shall try to address the same.
 

[Alienbeing]

Hi, kareemsa is correct as I use Loadcells everyday at work along with a National Instruments data acquisition system. I just wanted to note here that doing a calibration of the loadcell with known identical value weights is how I calibrate my 40 lb. loadcells. After taking 10 measurements and record the voltages as I add weights I then run a linear regression analysis on the measured values to get my final sensitivity.
This is the way I was instructed to get a more accurate sensitivity for the loadcell. Also using calibrated weights is ideal.

Alienbeing