Calibration

What is calibration? Calibration is the activity of checking, by comparison with a standard, the accuracy of a measuring instrument of any type. Instrument calibration is one of the primary processes used to maintain instrument accuracy. The instrument can then provide more accurate results when samples of unknown values are tested in the normal usage of the product. Calibration is required for:

• Testing a new instrument
• Testing an instrument after it has been repaired or modified
• Periodic testing of instruments
• Testing after the specific usage has elapsed
• Prior to and/or after a critical measurement
• When observations are not accurate
• After events such as:
• An instrument has had a shock, vibration, or exposure to adverse conditions.
• Sudden weather changes

Why Calibrate Instruments? There are many reasons why measurement instruments should be maintained in a state of proper calibration. To some extent, these may be self-evident, but the main ones relate to the need to ensure different measurements fit together, and that measurements have a definite quality and are fit for the purposes for which they were made. Calibration allows errors and uncertainties to be quantified, which allows their proper use in deriving later information, and ultimately forming a high-quality foundation for the decision-making that results from survey work. Calibration should ultimately provide a definite chain from a given instrument back to the national measurement standards. This provides a guarantee of measurement quality. Calibration of measurement instruments is simply good professional practice. It builds professional credibility, simply by ensuring that the measurements that are produced are high quality and connected to the standards.