You may have encountered this term many times and must have wondered what calibration is? The term calibration is used frequently in various Engineering subjects which may raise question in your mind what is calibration and how we calibratevarious instruments and devices used in Engineering, Medical and various other fields. If this is the same case with you then let us through some light on the topic calibration which will enlighten and enrich your knowledge about your subject.

What is calibration?

lets start with an example of ‘time’. Every one uses watches and if not watches then you have mobile phones to have a track of time. Have you ever wondered what Time is? Its not the digit in our phones or the distance traveled by the hands of your watches. So getting into some technicalities, let me tell you how physics defines “second” :-

“The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom”

In simple terms one second is the time needed for a cesium-133 atom to perform 9,192,631,770 complete oscillations which means time has been compared with a known reference value, cesium-133 atom here which is known to be universal.

And that exactly defines what calibration is– comparing with known reference value. Now the question arises why calibrate? Yes i am getting into that, patience.

Need for calibration

The main reason for doing the calibration is that with time, even the best instruments drift and loose their ability to provide accurate measurements. This in turn makes calibration necessary.

Lets take an example of proving ring.

Proving rings are used to calibrate the amount of force used in various testing machines used in Mechanical Engineering. Once the calibration is done, other materials are placed in that device which helps scientists and engineers to determine exact strength of materials.

Why Calibration is important?

• To help keep high and consistent product quality
• Optimize process
• keep a check on quality of measurements
• other safety reasons
• To ease the users by providing units of various quantities (splitting time into seconds, minutes and hours i.e giving time some digits)

Risk and cost of not calibrating

So what if we do not calibrate? These are some of the consequences which we may face without calibration.

• Unscheduled production downtime, quality problems and product recalls
• risking safety of employees
• risking safety of consumers and customers
• direct economic losses in business based on measurement