What is a non compensating instrument?

A non-compensating instrument is a measuring device that does not provide any form of automatic correction for environmental factors such as temperature or humidity. These instruments generally provide readings that are accurate at or near calibration conditions, but may be subject to errors when used in different environmental conditions. Examples include mechanical calipers, micrometers, and non-compensating strain gauges. For high accuracy measurements where environmental factors may vary, compensating instruments or additional means of error correction are often necessary.