Fig 1: Trundle wheel with counter
Summary
A wheel used for measuring long distances.
Operation
Trundle wheels have been used for many years to measure long distances fairly accurately. Older units consist of a wheel and handle. The wheel has a small segment that comes into contact with the handle section making a clicking sound every metre that the wheel travels. By counting the clicks, the operator is able to calculate distances much easier than by using surveyor tapes.
Modern units may incorporate a counter which provides more accuracy and digital trundle wheels are very accurate.
Safety
The contents of this page are for information only. Please refer to CLEAPSS or ASE safety advice and/or publications before undertaking any preparation, practical experiment or using any equipment featured on this site or any other.