Why and When to Calibrate

Why calibrate?

Regular calibration provides you with:

• Knowledge and evidence of how your instrument measures – now and over time
• Reliability – you know your instrument works correctly

According to ILAC, International Laboratory Accreditation Cooperation, calibration is:

• To reassure the uncertainty that can be achieved with the measuring instrument
• To confirm whether or not there has been any alteration of the measuring instrument which could introduce doubt about the results delivered in the elapsed period
• To improve the estimation of the deviation between a reference value and the value obtained using a measurement instrument and the uncertainty in this deviation, at the time the instrument is actually used

When to start calibration

We recommend calibrating  your instrument prior to use. The easiest way is for you to order initial calibration with the new instrument.

That way you start measurement history, which can be required by your customers or quality procedures, from day one, .

How often?

How often you calibrate your instrument is a balance between risk and cost. The shorter the period between calibrations, the lower the risk of questionable measurements. We, therefore, recommend annual calibration for electrical instruments.

Equipment used on a daily basis will have a shorter cycle than equipment used, for example, once a month. However, you should take into consideration:

Cost:

• Cost of necessary correction measures - when you discover that the instrument has not been reliable over a long period of time

Instrument:

• The required uncertainty in measurements
• Extent and severity of use
• Trend data obtained from previous calibration records and tendency to wear and drift*

Environmental conditions, transportation and personnel:

• Climatic conditions, vibration, ionizing radiation, etc.
• Transportation arrangement
• Degree to which the  personnel are trained

* As components age and equipment undergo changes in temperature or sustain mechanical stress, critical performance gradually degrades. This is called “drift”. When this happens, your test results become unreliable and both design and production quality suffer. While drift cannot be eliminated, it can be detected and contained through the process of calibration.