Steel rules do not rule

The answer is clear, according to Mike Mathias, chairman of CFTS, the accrediting body for the 450+ members of the national scheme for carrying out Thorough Examinations on materials handling equipment of almost every type. 

“When checking for chain wear and elongation we require our members to use a precision, self-calibrating chain wear gauge. It is our view that measurements obtained using a steel rule or tape offer greater scope for error, so cannot be guaranteed to deliver accurate, reliable and replicable results.

“Insisting on an accurate chain gauge is one of the operational methods that differentiates CFTS Thorough Examinations from most others.”

CFTS favours the chain gauge because its V-shaped jaws always give positive location on the pins, so that readings are always from the pin’s centre. This means results are both consistent and repeatable.  

By contrast, using a tape or steel rule requires a totally steady hand, along with very precise visual alignment, which, depending on the position of the inspector’s eyes, can result in a parallax error. In the field this makes it almost impossible to achieve genuine consistency.