Why should I calibrate?
All instruments lose accuracy over time due to normal usage and the environmental conditions to which they are exposed.
How often should I calibrate?
For most applications, the recommended calibration interval is every twelve months.
What is NIST Calibration?
NIST stands for the National Institute for Standards and Technology. This organization is responsible for maintaining the master for different measurements, such as the standard "foot", standard, "second", or standard "pound". NIST also maintains the standard for temperature, humidity and pressure.
NIST Traceable means that the measuring standard can be traced directly back to the master standard maintained by the NIST organization.
NIST-Traceable does not tell you the measurement accuracy of a metrologty service in any detail. Only metrology services that can document their ISO 17025 standard provided data on their best measurement uncertainty.