This document discusses different types of transducers and their industrial applications. It focuses on flow measurement transducers, describing the orifice plate and venturi tube in detail. The orifice plate uses a pressure drop created by a hole in a plate to measure flow. The venturi tube uses a more gradual restriction to create differential pressure, making measurements closer to theoretical values and less sensitive to disturbances than the orifice plate. Both are widely used in industry as differential pressure flowmeters.

1. TRANSDUCERS & ITS
INDUSTRIAL APPLICATIONS
PRESENTED BY
AJAY KUMAR
ROLL NO. 1305232005
E.I ,III YEAR

3. TYPES OF TRANSDUCERS
PRESSURE MEASUREMENT
TEMPERATURE MEASUREMENT
FLOW MEASUREMENT

14. FlOW MEASUREMENT
• ORIFICE PLATE
• VENTURI TUBE
• ROTAMETER

15. Differential Pressure Flowmeters
The Orifice Plate
• The orifice plate is the simplest and cheapest. It is
simply a plate with a hole of specified size and
position cut in it, which can then clamped between
flanges in a pipeline
• The increase that occurs in the velocity of a fluid as it
passes through the hole in the plate results in a
pressure drop being developed across the plate.
• After passing through this restriction, the fluid flow jet
continues to contract until a minimum diameter
known as the vena contracta is reached.

17. The Venturi Tube
• The classical or Herschel Venturi tube is the oldest type of differential pressure
flowmeter (1887).
• The restriction is introduced into the flow in a more gradual way
• The resulting flow through a Venturi tube is closer to that predicted in theory so
the discharge coefficient C is much nearer unity (0.95).
• The pressure loss caused by the Venturi tube is lower, but the differential pressure
is also lower than for an orifice plate of the same diameter ratio.

18. • The smooth design of the Venturi tube means that it is less
sensitive to erosion than the orifice plate, and thus more
suitable for use with dirty gases or liquids.
• The Venturi tube is also less sensitive to upstream
disturbances, and therefore needs shorter lengths of straight
pipework upstream of the meter than the equivalent orifice
plate or nozzle.
• Like the orifice plate and nozzle, the design, installation, and
use of the Venturi tube is covered by a number of
international standards.
• The disadvantages of the Venturi tube flowmeter are its size
and cost.
The Venturi Tube