The ELC-30S is a resistive strain gage type load cell. It is used to determine load in rock bolts, tieback anchors etc through a centre hole. It is based on Wheatstone bridge principle and has eight 350 Ohm resistance strain gages, wired to form a 700 Ohm bridge, inside a cylinder of high steel strength.
 
These eight gages are mounted around the circumference at 45 degrees to each other. The load cell is resistive to ingress of water and corrosive environment by sealing hermetically using the electron beam welding technique.