What is Environmental control so important?

The answer is accuracy.

At our premises in Guildford, Surrey we are proud to house an environmentally controlled metrology cell, in which lighting and temperature is controlled, both of which are fundamental for dimensional metrology. Here we maintain the standard reference temperature of 20° according to the International standard. This constant temperature reduces the thermal expansion of materials, ensuring the highest level of accuracy is achieved.

It is important to constantly track temperature, humidity and barometric pressure fluctuations so that we can ensure the environmental conditions within the measurement area are consistent.  This is especially important for long term projects where part measurements do not all have to be completed in one batch, at one time.  This helps our customers to send parts as they are ready, reducing down time and increasing flexibility.

At Physical Digital we track the performance of our sensors by performing regular acceptance tests against a calibrated artefact.  By analysing key dimensions, we can perform statistical process control against our set control limits.  This will identify any non-conformance, which could be related to incorrect measurement set-up or variation in environmental control. Our probing and spacing artefact is periodically calibrated to international standards enabling analysis of bias and performance of the measurement system.

An additional benefit to accurate environmental control is the ability to measure and inspect customer parts as close to the designed condition as possible.  Although the accuracy of the measurement would not be affected, by not measuring parts at a consistent 20° would mean offsets or bias would need to be applied to inspect dimensions to design drawings.  Although this will only have a small effect to the measurement and inspection, for tight tolerance and critical components, all uncertainties must be considered.