Line standard and End standard

The measurement of distance can be done by 2 methods.

a)      We can measure the length as the distance between 2 lines.

b)      Or we can measure the length as the distance between 2 parallel faces.

Depending upon this method of measurement, the measurement kof distance is classified into 2.

1)    Line Standard

If the distance is measured as the length between 2 parallel lines it is called line standard.   Examples: The scale is a good example for line standard.  A scale with divisions shown as lines is used as the measurement.

Characteristics of line standards

Accuracy is less because the thickness of the calibrated lines on the scale is not taken into account during measure.

·       Scale is quick and easy to handle over a wide range.

·       Scales are subjected to paralyse error.

·       Scales markings are not subjected to wear.

2)    End standards

When the length is measured as the distance between 2 faces, it is known as the end standards.  Examples:- Slip gauges, micrometer anvil, venier calliper etc.

Characteristics of end standards

·         High accuracy.

·         Time for measuring is high and cannot measure 2 or more length simultaneously.

·         Subjected to wear on their faces and because of that, we are forced to built the gauges with hard materials.

·         They are not subjected to paralyse error.