It contains the slides which tells the the types of pressures and its ways to measure in Instrumentation and Process Control

1. SUBMITTED BY :-
RAHUL GUPTA (249/14)
VISHAL DHAKA (267/14)
III B.TECH
Leather Technology
H.B.T.U. Kanpur-208002

2. (1) Pressure Measurement of gas and liquid is require in most of
the industries for operate and control.
(2) Pressure = FORCE/AREA .
(3) Only that force, which is perpendicular to the surface is used
to calculate the pressure.
(4) The units of pressure that we used mainly are pound per
square inch(psi) and newton per square inch(SI).

3. Types Of
Pressure
Gauge
Pressure
Absolute
Pressure
Vacuum
Pressure
Velocity
Pressure

4. Their are mainly three methods for pressure
measurement -
Manometer method
Elastic Pressure transducers
Pressure Measurement by Measuring
Vacuum

5. (1) MANOMETERS
-
It is the simplest measuring
instrument used for gauge
pressure measurements, by balancing the pressure against the weight
of column of fluid.
a) U-tube Manometer :- If the pressure on one limb of
a U tube is greater than the other this difference in
pressure can be measured by simply finding the
DIFFERENCE in height (h) of the liquid in the two
limbs of the U tube.

6. b) Well-type Manometer :- The main
difference between a U-tube manometer
and a well type manometer is that the U-
tube is substituted by a large well such that
the variation in the level in the well will be
negligible and instead of measuring a
differential height, a single height in the
remaining column is measured.
c) Barometer :- A barometer is a
well-type absolute pressure gauge whose
pressure range is from zero absolute to
atmospheric pressure.

7. d) Inclined Manometer :- Inclined manometers are more
sensitive than vertical column manometers. Initially, when there is
no fluid flowing in the pipe the level of manometer liquid is at
XX’. But due to liquid pressure in the pipe the level of manometer
liquid moves down from XX’ to YY’ in the tank and rises in the
right limb to the distance h2 from XX’.

8. e) Micro-Manometer :- A micro-
manometer is a special type of
manometer designed to measure
extremely small differences in
pressure.
ADVANTAGES
• Easy to fabricate and relatively
inexpensive;
• Good accuracy;
• High sensitivity;
• Require little maintenance
• Specially suitable for
low pressure and low differenti
al pressures
DISADVANTAGES
• Usually bulky and large in size.
• Being fragile, get broken easily.
• Readings of the manometers
are affected by changes in
temperature, altitude and gravity.
• A capillary effect is created due to
surface tension
of manometric fluid

9. • It is frequently used pressure gauge because of its simplicity and
rugged construction.
(a) C-type Bourdan Type Pressure Gauge
• Diaphgram are widely used for gauge pressure and draft
measurements, particularly in very low ranges(0-4mm).
(b) Diaphgram Pressure Transducers
• The bellows-type gauges are used for the measurement of
absolute pressures.It is more sensitive than Bourdan-tube
gauges.
(c) Bellows

10. Vacuum pressure are those which are below
atmospheric. With modern vacuum pressure
system, it is possible to obtain pressures from
1000 m bar.