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What is calibration?

The International Bureau of Weights and Measures (BIPM) defines calibration as: “Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or secondary standard) and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication.

What Prompts calibration?

Calibration may be required for the following reasons:

  • a new instrument
  • after an instrument has been repaired or modified
  • moving from one location to another location
  • when a specified time period has elapsed
  • when a specified usage (operating hours) has elapsed
  • before and/or after a critical measurement
  • after an event, for example
  • after an instrument has been exposed to a shock, vibration, or physical damage, which might potentially have compromised the integrity of its calibration
  • sudden changes in weather
  • whenever observations appear questionable or instrument indications do not match the output of surrogate instruments
  • as specified by a requirement, e.g., customer specification, instrument manufacturer recommendation.

What are the range of Calibration services the SON undertakes?

Measuring devices and instruments are categorized according to the physical quantities they are designed to measure. These vary internationally, and cover instruments that measure various physical quantities such as electromagnetic radiation (RF probes), sound (sound level meter or noise dosimeter), time and frequency (intervalometer), ionizing radiation (Geiger counter), light (light meter), mechanical quantities (limit switch, pressure gauge, pressure switch), and, thermodynamic or thermal properties (thermometer, temperature controller).

The National Metrology Institute(NMI) of SON undertakes calibrations in the fields of Mechanical (Mass Length and Dimension, Volume, Flow, Pressure, Force), Thermodynamics or Thermal properties(Temperature), and Metrology in Chemistry. For details of these services see the attached corporate profile of the NMI in the link below