Proving rings are used for load measurements and are used in outfits of a number of Soil / Cement & Bitumen Testing Equipments like Direct Shear Test Apparatus, Triaxil Shear Test Apparatus, C.B.R. Test, Uncontined Test, Marshall Test etc. 
They are made out of special steel carefully forged to give maximum strength and machined to give highest sensitivity combined with stability to ensure long life and accuracy. When compressive or tensile load is applied within the elastic range, the proving rings get temporarily deformed. This deformation is measured by a sensitive dial gauge fixed co-axially at the center of proving ring. The dial gauge readings thus obtained versus load applied enable the operator to find out unknown load, just by noting the dial gauge reading for unknown load. The proving rings have high elasticity and on removing load they regain their original shape provided they are loaded in their elastic limits.
Salient Features

• A Dial gauge and plunger anvil are mounted on brackets clamped to the ring body. The dial gauge is held perfectly rigid without the remotest chance of shifting due to inadvement shocks or pressures exerted on it. The dial gauge plunger rests on an adjustable anvil. Proving Rings , from 50 kg to 1,00,000kg capacity provided with 1/2 inch B.S.F femal threads. Loading bosses and a loading ball nipple and steel ball are supplied with each rings. Rings of capacity over 25000kg (or 25 Tonnes) are not thus threaded. Each ring is individually calibrated and supplied with works calibration chart and a carrying case.
  Calibration charts from Standard Laboratories for the Proving Rings ordered are also available at extra cost.
  All Proving Rings are Integral Type.
  Integral type Compressive Proving Rings of different capacities from 50kgf to 200000kgf are available.
  (a) above cap. 50 to 500kg.
  (b) above cap. 500 to 3000kg.
  (c) above cap. 3000 to 5000kg.
  (d) above cap. 5000 to 10000 kg.
  (e) above cap. 10000 to 20000 kg.
  (f) above cap. 20000 to 30000kg.
  (g) above cap. 30000 to 50000 kg.
  (h) above cap. 50000 to 100000 kg.
  (i) above cap. 100000 to 200000 kg.
  (j) above cap. 200000 to 300000 kg.

Tension Compression Proving Rings are having standard 1/2" (BSF Threads) and for measuring tension , 2 nos. Tension rods having male threads at both ends are supplied. 
For measuring loads in compression these tension rods are removed and the ring can be used in usual way. Works calibration charts for tension and compression are supplied with each ring . Supplied complete with tension rods in a carrying case. 
Note : We can also supply the following Proving Rings. 1. Tension cum compression proving ring upto 10,000kg capacity. 2. Double proving rings.