calibration chains

WHY ARE CALIBRATION CHAINS STILL BEING USED?

Calibration chains are still widely used to calibrate belt weighers, weightometers and conveyor belt scales. BAMAU GROUP does not consider them the preferred method for achieving an accurate, repeatable calibration.

A belt weigher is fundamentally a linear measuring instrument. A known static load applied directly to a correctly installed weigh frame provides a fixed and repeatable calibration reference.

A calibration chain introduces another mechanical variable.

As individual chain links travel across the weigh idler and adjacent idlers, the distribution of the applied load continually changes. Move the chain forwards or backwards on the conveyor and the indicated load can change simply because the links are sitting in different positions relative to the weighing system.

That is not a better calibration reference.

More importantly, calibration chains can hide the actual problem.

If an empty conveyor belt does not maintain consistent contact with correctly aligned weigh and adjacent idlers, the belt weigher can have a poor or unstable zero. Applying a heavy calibration chain forces the belt into contact with the rollers and can temporarily mask the mechanical condition causing the production error.

The result can be a belt weigher that appears to calibrate correctly with a chain but still produces inaccurate results once the chain is removed.

BAMAU’S PREFERRED CALIBRATION HIERARCHY

1. Material test / belt cut

2. Certified static test weights or BAMAU SIP weights

3. Electronic reference calibration where appropriate

4. Calibration chains

BAMAU Zero-Flex weighing idlers and custom weigh frames are designed around the natural belt profile, correct roller alignment and consistent belt contact — addressing the mechanical conditions that often lead operators toward calibration chains in the first place.

We can service and calibrate existing systems that use chains, but where practical we will identify the underlying reason they are required and recommend a safer, simpler and more repeatable calibration method.

If your belt weigher only calibrates accurately when a calibration chain is installed, the chain may not be solving the problem — it may be hiding it.