1.    A dead weight tester

2.    Manometer

Elastic transducers ( Force summing Transducers)

1.    Bourdon tube pressure gauge

2.    elastic diaphragm gauges

3.    bellow gauges

4.    Bellow gauges to measure gauge pressure

5.    Bellow gauge to measure differential pressure

Strain gauge pressure cells.

1.    Flattened tube pressure cell (PINCHED TUBE).

2.    Cylindrical type pressure cell.

Mcleod vacuum gauge.

1.    Thermal conductivity gauges.

Pirani gauge.

1.    Thermocouple type conductivity gauge.

Ionisation gauge

1.    bulk modulus or electrical resistance pressure gauge.

The above instruments are used in following situations:

Type of pressure to be measured	Pressure Measuring instrument to be used
Low pressure	Manometer
High and medium pressure	Bourdon tube pressure gauge.Diaphragm gauge.Bellows Gauges.
Low vacuum and ultra high vacuum	Mcleod vacuum gaugethermal conductivity gauges.Ionisation gauges.
Very high pressures	Bourdon tube pressure gauge.Diaphragm gauge.Bulk modulus pressure gauge.