Soil test calculation.. Part

[Karegowd]

How to change proving ring reading into load..
I know formula that is
Load= proving ring reading *proving ring constant
But here what is the value of proving ring constant..

 

[oldestguy]

You take it to a testing lab and apply loads while reading the gauge. Just don't over stress it. Supposedly the machine applying the loads has been calibrated. Chances are the load multiplying factor is some constant for the range of loads it is used for. The supplier of the proving rung should have done this, but it is not difficult. I've made proving rings from the outer race of large ball bearings used in big construction machinery. Attaching the gauge to the ring takes a little shop work however. I found those bearings in the junk bin at a large repair shop.

If in a hurry and no way to get to a testing lab, take your bath room scale and a scissor jack to a car. Set the ring on the scale with the jack on top and lift the car some for weight. Take a few different loads. This would be a rough way to get in the ballpark of the load calibration.

 

[Ron]

Also, most proving rings have a serial number. The manufacturer of the proving ring should have the initial calibration curve. While it might be out of date for critical calibration, it gives you an idea if your secondary calibration as OG described is close.

 

[Karegowd]

I am not get exact answer

 

[Ron]

The proving ring constant is unique to each proving ring. It has to be calibrated to determine that constant. You cannot apply a random constant....it must be empirically determined.

 

[mikeofBelAir]

Back in the day, we used to stack the weights from the consolidometer on top of the proving ring and take readings...always "assuming" the weights were perfectly uniform. Since we had a bank of about 14 mechanical-arm consolidometers, we had quite a supply of weights. Do enough points and we got a reliable factor. Had to be careful to keep the stack centered so it didn't all topple over. Just don't deform the ring.

 

[L0k]

That is very simple, Karegowd. It needs weights.
- place the proving ring in the flat bench
- place the weight load on top of the proving ring & read the dial
- do the above step several times up to the maximum proving ring capacity, but not to exceed it.
- draw the curve loads vs dial readings, you shall get the straight line
- the tangent line may guide you to the load/proving ring division as the proving ring constant.