Lesson 1.5
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MANOMETER
Manometer is an instrument which can measure the pressure
Difference between two points. It can measure the pressure
Up to 30 psi.
Manometer is made up from glass ,fiber ,pvc tube means
transferent material.
• In manometer, manometric fluid used are mercury, alcohol,
oil, water.
Lesson 1.5
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TYPES OF MANOMETER
U TUBE MANOMETER
OPEN U TUBE MANOMETER
INCLINED TUBE MANOMETE
WELL TYPE MANOMETER
RING TYPE MANOMETER
DIFFERENTIAL MANOMETER
LESSON NO. 1.5 CHARESTRIC OF
MANOMETRIC FLUID
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SPECIFIC GRAVITY SHOULD BE CONSTANT.
DENSITY IS GREATER THEN PROCESS FLUID.
INSOLUBLE IN PROCESS FLUID.
NON REACTIVE.
SHINING LIQUID.
DONT WET THE MANOMETER SURFACE.
LOW FREEZING POINT.
HIGH BOILING POINT.
LOW VAPOUR PRESSURE.
U –TUBE MANOMETER
U –TUBE MANOMETER
– SIMLE FORM OF MANOMETER,WHEN IS
USED FOR EXPERIMENTAL WORK IN
LABORATORIES
– CONSTRUCTION :
– CONSISTS OF GLASS TUBE IN U SHAPE
– PARTIALLY FILLED WITH A LIQUID
– WATER AND MERCURY ARE USED
BECAUSE THEIR SPECIFIC WEIGHTS FOR
VARIOUS TEMPERATURE ARE KNOWN
AND THEY DO NOT STICK TO THE TUBE
– ONE END OF TUBE IS CONNECTED TO LOW
PRESSURE TAP
– OTHER END CONNECTED TO HIGH
PRESSURE TAP
– THE DIFFERENCE IN PRESSURE(P1_- P2) IS
OBTAINED.
P= (ρ- ρ1 ) gh
ρ = DENSITY OF FLUID IN UTUBE
ρ1= DENSITY OF FLUID WHOSE
PRESSURE TO BE
MEASURED
h= DIFFERENCE IN FLUID
LEVELS
g= ACCELERATION DUE TO
GRAVITY
ERRORS IN MANOMETERS
• EFFECT OF TEMPERATURE :
• VARIATION IN TEMPERATURE, VARIATION
IN READING DUE TO REDUCTION OF
DENSITIES OF FLUIDS, TEMPERATURE ↑ , THE
FLUID EXPANDS.
– CAPILLARY EFFECT :
• USING SAME FLUID IN BOTH LEGS EFFECT
WILL BE NEGLECTED.
ADVANTAGES AND DISADVANTAGES
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ADVANTAGES:
SIMPLE CONSTRUCTION.
HIGH SENSITIVITY AND ACCURACY.
REASONABLE COST.
SUITABILITY FOR LOW PRESSURE
APPLICATIONS.
DISADVANTAGES:
LARGE AND BULKY.
NEED FOR LEVELING.
NO-OVER RANGE PROTECTION.