Question

Industrial measuring instruments are of accuracy classes
1. 0.5 and 1
2. 0.5, 1, 1.5, 2.5 and 5
3. 1, 1.5, 2.5 and 5
4. 1.0, 0.2 and 0.5

Answer 1

Correct Answer - Option 1 : 0.5 and 1

Accuracy:

• The ability of the instrument to measure the accurate value is known as accuracy.
• In other words, the closeness of the measured value to a standard or true value.
• Accuracy is obtained by taking small readings.
• The accuracy of the system is classified into three types as follows:

Point Accuracy

• The accuracy of the instrument only at a particular point on its scale is known as point accuracy.

Accuracy as Percentage of Scale Range:

• The uniform scale range determines the accuracy of a measurement.
• Consider a voltmeter having the scale range up to 500 V. The voltmeter has an accuracy of ±0.5%, i.e. ±0.5% percent of increase or decrease in the value of the instrument is negligible. But if the reading is more or less than 0.5%, it is considered a high-value error.

Accuracy as Percentage of True Value:

• Such type of accuracy of the instruments is determined by identifying the measured value regarding their true value.
• The accuracy of the instruments is neglected up to ±0.5 percent from the true value.
• Industrial measuring instruments having accuracy classes is generally 0.5 and 1.