Before using gauge instruments, what must be checked?

Before using gauge instruments, it is crucial to check their operation and accuracy. This ensures that the instruments are functioning as intended and providing reliable readings, which is essential for maintaining safety and compliance during the installation or retrofitting process.

Operation refers to whether the gauge is working properly—it should be able to display readings consistently without any issues. If the operation is compromised, it could lead to faulty measurements that could affect system performance or safety.

Accuracy, on the other hand, assesses whether the gauge provides correct readings. Inaccurate gauges can mislead operators and technicians in critical situations, potentially resulting in improper handling of materials, unsafe conditions, or regulatory compliance failures. By verifying both the operation and accuracy of the gauge, technicians can ensure that they are making informed decisions based on trustworthy data.

The other options include relevant factors but do not encompass the critical aspects of operational reliability and measurement validity as effectively as operation and accuracy do.