Grand Rapids Metrology (United States) - Load cells used in truck scales or rail scales are exposed to temperature-induced expansion and contraction. Canister load cell technology couldn’t account for the temperature-induced errors, so rocker column load cells were developed to replace them.
Rocker column load cells have rounded upper and lower loading surfaces that are spaced out from the strain gages. This is to avoid stresses from the high contact areas. Spherical radii are either placed on the loading surface or where the load measurement is made and at the outer extremities. This is to avoid dispositioning as the column rocks and minimize errors caused by weighbridge shortening. It is important to choose a rocker column load cell that will compensate for when the load cell is offset. Rocker column load cells should also be hermetically sealed at both the strain gage location and cable entry. Compensating for load errors are vital to obtaining accurate measurements and meeting quality standards.
Truck scales are often used to sell products by weight, so they need to meet NTEP quality standards. It is important to have the correct load cell cup installed! Here’s a video to help you make sure you have the right cups for your rocker column load cells.