![• The piezometer function is dependent on
the pressure changes. Any change in
pressure deflects the diaphragm
proportionally and this, in turn, affects the
tension in the stretched wire. Thus any
change in pore pressure directly affects the
tension in the wire.
• The wire is plucked by a coil magnet.
Proportionate to the tension in the wire, it
resonates at a frequency ‘f’, which can be
determined as follows:
f = {[σg/ρ] ^1/2}/ (2l) Hz
Where σ = tension of the wire
g = gravitational constant
ρ = density of wire
l = length of wire
• The resonant frequency, with which wire
vibrates, induces an alternating current in
the coil magnet. This explains the
piezometer equation or the formula. 7](https://image.slidesharecdn.com/manometers-230711082057-459a5d5b/85/Manometers-pptx-8-320.jpg)
Manometers.pptx
- 1. Department of aeronautical engineering Subject: Fluid Mechanics Topic: MANOMETERS Team Members NAME USN Srushti Shashikanth Joshi 1NT21AE079 Rehamath M 1NT21AE063 Priyanka V 1NT21AE060 Tejaswi Teradal 1NT21AE084 Submitted to: Mrs. Sreelakshmi Date: 10-02-2023 1
- 2. What is Manometer? An instrument for measuring the pressure acting on a column of fluid, consisting of a U- shaped tube of liquid in which a difference in the pressures acting in the two arms of the tube causes the liquid to reach different heights in the two arms. 2
- 3. Types of Manometers MANOMETERS SIMPLE MANOMETER DIFFERENTIAL MANOMETER PIEZOMETER U-TUBE MANOMETER SINGLE COLUMN MANOMETER VERTICAL COLUMN MANOMETER INCLINED COLUMN MANOMETER U- tube Differential Manometer Inverted U- tube Differential Manometer 3
- 6. • Piezometers or pore pressure meters are the pressure transducers that are installed beneath the ground to measure the sub-surface piezometric level within groundwater level, soil, or rock. • Piezometer is extensively used in Groundwater Monitoring to determine the level and flow pattern of groundwater. 5
- 7. • It converts water pressure to a frequency signal via a diaphragm and a tensioned steel wire. • A change in pressure on the diaphragm causes a change in tension of the wire. • When excited by a magnetic coil, the wire vibrates at its natural frequency. • The vibration of the wire in the proximity of the magnetic coil generates a frequency signal that is transmitted to the readout device. • The readout device processes the signal and displays a reading. • Calibration factors, which establish a relationship between pressure applied to the diaphragm and the frequency signal returned to the readout device, are used to convert Hertz readings to Voltage. 6
- 8. • The piezometer function is dependent on the pressure changes. Any change in pressure deflects the diaphragm proportionally and this, in turn, affects the tension in the stretched wire. Thus any change in pore pressure directly affects the tension in the wire. • The wire is plucked by a coil magnet. Proportionate to the tension in the wire, it resonates at a frequency ‘f’, which can be determined as follows: f = {[σg/ρ] ^1/2}/ (2l) Hz Where σ = tension of the wire g = gravitational constant ρ = density of wire l = length of wire • The resonant frequency, with which wire vibrates, induces an alternating current in the coil magnet. This explains the piezometer equation or the formula. 7
- 10. It is an instrument that measures blood pressure that contains an inflatable rubber cuff, which is cloaked around the arm. A measuring device indicates the cuff's pressure or tension, especially in arteries. 9
- 11. Types of a Sphygmomanometer 1. Mercury Sphygmomanometer 2. Aneroid Sphygmomanometer 3. Digital Sphygmomanometer Mercury sphygmomanometer Aneroid sphygmomanomete r Digital sphygmomanometer 10
- 12. Bladder: It is an inflatable bag that, when filled, squeezes the arms to block the artery. Cuff: The cuff has an inflatable rubber bladder that is cloaked around the upper arm. A pressure meter indicates the cuff's pressure. Valve: The deflation valve allows for controlled deflation of the cuff and it’s critical for accurate measurement. An end check valve prevents air from escaping. Bulb: A small, handheld air pump inflates the blood pressure inside the cuff. Manometer: It is the portion of the sphygmomanometer that measures the blood pressure in mm of Hg. This aneroid gauge contains a watch-like movement that measures the air pressure applied to the cuff. Within the gauge, there is a series of diaphragms (of copper or beryllium) that expands when air is filled and contains gears that transform the linear motion of diaphragms, turning the needle on a dial calibrated in mmHg. Parts of a Sphygmomanometer 11
- 13. WORKING PRINCIPLE OF SPHYGMOMANOMETER The pressure indicators of all mercurial sphygmomanometers consist, essentially, of a glass U tube partly filled with mercury. If one of the legs of the tube is connected to an arm bag under pressure and the other left open to the air, the mercury will fall on the side connected to the bag and rise on the other side, until the pressure exerted by the excess of mercury in one leg over that in the other is equal to the difference between the pressure in the bag and atmospheric pressure. Since in blood-pressure measurements it is customary to express the pressure in terms of the height of the mercury column supported by the pressure in the bag, it is only necessary to measure the vertical distance between the two mercury levels in the tubes. 12
- 15. It is an instrument used for measuring the pressure of gases or liquids, consisting of a semicircular or coiled, flexible metal tube attached to a gauge that records the degree to which tube is straightened by the pressure of gas or liquid. The bourdon tube is the basic mechanisms for sensing pressure. What is Bourdon tube? 14
- 16. PRINCIPLE OF BOURDON TUBE PRESSURE GAUGE A Bourdon tube is subjected to a pressure ,it deflects. This deflection is proportional to the applied pressure when calibrated. 15
- 17. DESCRIPTION OF BOURDON TUBE PRESSURE GAUGE A Bourdon tube is fixed and open at one end to receive the pressure which has to be measured. The other end of the bourdon tube is free and closed. The cross-section of the bourdon tube is elliptical. The bourdon is in a bent form to look like a circular arc. To the free end of the bourdon tube is attached an adjustable link, which is in turn connected to a sector and pinion . To the shaft of the pinion is connected a pointer which sweeps over a pressure calibrated scale. 16
- 18. WORKING OF BOURDON TUBE PRESSURE GAUGE • The open end of this coiled tube is fixed in place and other end is sealed and free to move. • When a fluid that needs to be measured is directed into the open end of the tube, the unfixed portion of the coiled tube tends to straighten out. • The higher the pressure of the fluid the more the tube straightens. • When the pressure is reduced, the tube recoils. A pointer is attached to this moving end of the tube, usually through a linkage of small shafts and gears. By calibrating this motion of the straightening tube, a face or dial of the instrument can be created. Thus, by observing the pointer movement along the scale of the instrument face positioned behind it, pressure increases and decreases are communicated to the pilot. 17
- 19. The Bourdon tube is the internal mechanism for many pressure gauges used on aircraft. Some of the instruments that use a Bourdon tube mechanism include the engine oil pressure gauge, hydraulic pressure gauge, oxygen tank pressure gauge, and deice boot pressure gauge. 18
- 21. WHAT IS A DIAPHRAGM PRESSURE GAUGE ? A diaphragm pressure gauge uses the deflection of a thin, flexible membrane to measure fluid pressure in a system. The diaphragm isolates internal components from the media, making this gauge suitable for corrosive or contaminated liquids or gasses. This gauge is used for low-pressure measurements, such as measuring atmospheric pressure or monitoring pressure in gas canisters. They are also referred to as flexible membrane pressure gauges. 20
- 22. PARTS OF THE DIAPHRAGM PRESSURE GAUGE 1. Pressure inlet: System media enters the pressure gauge at the pressure inlet (Figure 2 labeled C). The inlet has a threaded (e.g., NPT or BSP) or flanged process connection. 2. Diaphragm: The media presses against and proportionally deflects the diaphragm (Figure 2 labeled E). The diaphragm is a thin, circular, flexible, metal disc. It is typically made of stainless steel for corrosion and high-temperature resistance. • The disc can be corrugated or smooth. Smooth discs are only suitable for small deflections and therefore are unlikely to operate well in industrial applications. 21
- 23. 3. Housing:The housing securing the diaphragm has upper and lower components (Figure 2 labeled B). The lower housing connects to the pressure inlet and the upper housing supports the diaphragm in the case of high pressure .The two components can be flanged or welded together. Welded connections are preferable for sanitary applications. 4. Pointer: the movement of the pressure element proportionally translates to the pointer’s movements so a user can read the system pressure from the system pressure from the pressure gauge. 22
- 24. WORKING AND APPLICATIONS • There are two reasons to choose a diaphragm seal pressure gauge over other types. The first is when it is necessary for the system's media to not mix or contact the working parts of the gauge past the diaphragm. The second is for measuring low pressures. A diaphragm gauge can accurately measure pressure as low as 16 mbar (0.23 psi). As seen in the list below, a diaphragm pressure gauge is applicable in many different scenarios. • Pressure measurement in industrial and manufacturing processes, such as in chemical plants and power plants. • Pressure monitoring in pipelines and other fluid transport systems. • Pressure testing and calibrating in laboratory settings. • Pressure measurement in pneumatic and hydraulic systems. • Pressure monitoring in gas and liquid storage tanks. • Pressure measurement in HVAC systems, such as in boilers and air conditioning units. • Pressure monitoring in medical equipment, such as in blood pressure monitors. 23
- 25. • A digital diaphragm pressure gauge is a pressure sensor that utilizes a diaphragm with piezoresistive components. When a medium exerts pressure, the diaphragm bends, altering the cross-sectional area of the piezoresistive elements and leading to a change in their electrical resistance. This generates a voltage difference, which is then processed by the sensor's microprocessor to produce a pressure reading on the digital display. 24
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