Question

List and explain the measuring elements (stages) of a dial indicator starting with the primary sensing element

Answer 1

Variety of dial indicators exist in practical application we consider a bourdon tube pressure gauge.

The bourdon tube pressure gauge consists of Bourdon tube, gearing arrangement, linkage, pointer and dial

1) primary sensing element and variable conversion element

In bourdon tube pressure gauge the bourdon tube is the primary sensing element and variable conversation element. Here input is pressure. When pressure is applied at the open end of the bourdon tube the closed end of bourdon tube expands (primary sensing) and shows some displacement (variable conversion).

2) Data transmission element

In pressure gauge the linkage is the data transmission element. The linear displacement of the bourdon tube is converted to angular displacement by the linkage

3) variable manipulation and data processing element

The linkage is connected to a sector pinion arrangement. The displacement by the linkage is manipulated and converted into respective angular displacement by the pinion hence it is the data manipulation and processing element.

Data presentation element

The pinion arrangement is connected to a pointer. The pointer moves over a scale. The scale shows the pressure reading.