Know the Difference Between Accuracy and Precision

What is Accuracy

Accuracy of a measurement is how close it to the true value. From this we can know the value is deviated from the true value.

What is Precision

Precision measurement is the repeat-ability of measuring process, how far the different kind of measuring process uses same value that is precision.

Let’s see what is accuracy and precision in detail and difference between accuracy and precision. Accuracy and precision are both terms are associated with their measuring process only.

Difference between Accuracy and Precision

In simple words accuracy describes between the measurement and parts actual value where as precision describes variation you see when measure same part repeatedly with the same device.

By the following example the difference between accuracy and precision will be clearer from the below example :

Suppose assume that in a graph taking a frequency in x-axis and dimension in y-axis and with a true value of this one is around 25m with a diameter and this value now we are going to measure this by different measuring process and result will be like this below:

1. 1st value – 25.48 mm
2. 1st value – 25.52 mm
3. 1st value – 25.55 mm
4. 1st value – 25.56 mm

Here the above measures are from 4 measuring process ranging with different results was seen with a slight difference reading in numbers but the values are very close to each other, different kind of measuring process due to repentance here in above results with the true value. So the average value will be 25.48 mm, now the values here are very close to each other and here the 4 measuring process are precise and the average value is more deviated from the true value, so we can say the average value close to the true value (original value) is said to be precise but not accurate.

Precision measuring instruments

• Vernier Calipers ,Dial Varniar, Digimatic Varniar
• Micrometer
• Dial Bore gauge
• Pipe Dial Thickness Gauge
• Plunger Dial indicater
• Magnetic stand,Flexible mag stand
• Height gauge,Digimatic Height Gauge
• Bevel protector, Diagrammatic Bevel Protector.