Blog Post by Mitchell Barker & Jesse Wetherell
A test chain is a dynamic calibration tool used to simulate material loading on conveyor scales, belt scales or weigh feeders. Test chain calibration is used for testing mechanical belt scales, as well as to calibrate high capacity electronic belt scales that cannot be calibrated using a material test. The benefits of using a test chain are optimum calibration, dynamic loading simulation, and targeted test loading. For businesses with belt or conveyor scale applications, using a test chain for calibration will help assure the accuracy of your weighing equipment!
During the calibration, the test chain is applied to the conveyor belt and is secured at both ends so that the chain remains stationary over the scale’s weighbridge. The chain rolls on the surface of the moving conveyor belt, providing dynamic scale loading of a known weight value, and thus supplying the weight standard to perform a calibration service. The test chain simulates live material loading by causing the belt scale’s load cells to deflect simulating a load as if material is present. Test chains are designed for precise measurement, with each foot of chain weighing 50lbs.
Using a test chain for a much greater test load can be applied to high capacity belt scales and weigh feeders because most weighbridge designs can only accommodate a limited number of static weights applied to the scale. The high capacity test load is especially important on systems using mechanical weighing elements and lever systems because they calibrate the systems with test load values close to normal operating loads.
Businesses that work with metal recycling, aggregate, rock quarries, and other industries using belt scales will find that calibrating belt scales is both challenging and complex in nature, due to the fact of precarious locations of most belt scales. Therefore, one of the better tools to calibrate belt scales is a test chain (for outdoor applications). For example, a rock quarry with the initial pit feed conveyor may need to calibrate a high test load of 1500lbs or more with a test chain to achieve the best calibration results.
Below is a diagram of how a test chain would be set up on a conveyor. If you want more information regarding test chain rental for belt scales/conveyors and procedures with this calibration tool, contact the Sales team at Quality Sales Unlimited.
