PRESSURE GAUGES
Introduction:
Pressure gauges are devices that measure the rise and fall of pressure in a contained field. Eugene Bourdon was the first person to receive the first ever patent for a tube pressure gauge. Bourdon tube pressure gauge measures the pressure of various types of fluids including steam, water and air. Gears are connected to a coiled tube. The gears measure the pressures of fluids up to 10^5 psi. There is a wide variety of pressure gauges used in transportation, industry, medicine and mechanics of everyday life and recreation. Fig. 1.1: Bourdon tube Pressure Gauge
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They are designed so that liquid can be filled inside them. Casing is made of aluminium and has a solid front and blowout back for severe service. Industrial Gauges are dustproof and waterproof. Error is ± 0.4 % for every 18°F (10°C) temperature change from 68°F (20°C)
• LIQUID FILLED GAUGE
Due to the liquid filling, the adverse effects of severe environment is minimized. It also helps protect the internal of gauge and gives lubrication in the mechanism continuously. This kind of pressure gauges is suitable where pressure gauge is exposed to severe conditions. The casing is composed of stainless or Mild Steel and it is filled with silicon oil or glycerine. It is manufactured in standard pressure ranges from 0-1 kg/cm2 up to 0-1000 kg/cm2.
• COMPACT CAPSULE GAUGES
This type of gauges is particularly suitable for measurement of very low pressure or vacuum normally gases which are not corrosive to copper alloys. They are also confided in situations where gauges are exposed to mechanical vibration or pulsating pressure. They consist of smaller capsule of beryllium copper with option of mounting and connection M.S. case or cast aluminium weatherproof case. Standard pressure range in units of mmWC, mBar and inches of water
The purpose of this lab was to calculate the specific heat of a metal cylinder
The Split Hopkinson Pressure Bar is named after Bertram Hopkinson [2], who in 1914 acquired a technique to evaluate the pressures created by dynamic events such as the blast caused by a rifle bullet or the explosion of explosives. In this placement, a long cylindrical bar of steel is suspended horizontally by four equal threads so that it can dangle in the vertical plane parallel to it. A short piece of rod of the same diameter is obtained against the long bar by magnetic attraction created by a solenoid. A rifle bullet is forced out or gun cotton is detonated near the close of the long bar. This creates a pressure wave which goes from the long bar in the short piece of rod. On passing the loose end of the short rod the pressure wave is reflected back as a tensile wave; when the magnitude of the tensile wave exceeds that of the pressure wave at the butted end of the short rod, the inability of the short rod to hold up the tension along the joint produces separation and it flies away. The little rod is caught in a box suspended in
I removed the hand that was covering the hole of the tube when it was under the water of the bowl. The water remains inside the cylinder. all the way to the top, this will allow us to see how much gas is. given by the amount of water forced out of the tube. The delivery tube was then placed inside of measuring cylinder to.
Testing was performed at 23 ºC under the condition of 0% RH at 1 atm with the standard of ASTM D3985. Measurements were taken at three times and the average value was calculated. All specimens were conditioned at ambient conditions.
again to try and get as accurate results as possible. Diagram Apparatus Measuring cylinders. Stopwatch.com - a stopwatch. Beaker of water (Heat shield). Beaker.
estimate how much pressure boilers could withstand. They didn't always estimate correctly, as explosions were common. It was expensive to build and maintain the nineteenth century steamboats.
This law, known as Gay-Lussac’s law, observes the relationship between the pressure and temperature of a gas. Contrary to its name, this relationship was actually discovered by French scientific instrument inventor and physicist Guillaume Amontons, and is occasionally referred to Amontons’ Law of Pressure-Temperature. While Guy-Lussac did explore the temperature-pressure relationship, Guy-Lussac’s law is usually used to refer to the law of combining volumes. Amontons stubble across this relationship when he was building an “air thermometer.” Although not many have been able identify his exact method of experimentation, later scientist developed an apparatus in which consisted of pressure gauge and a metal sphere. These two pieces were then attached and submerged in solutions of varying temperatures. From Amontons’ and Guy-Lussac’s research and experimentation, they determined that pressure and volume had direct relationship; as one increased, the other increased. The quotient of pressure and temperature was then found to equal a constant, in which just like Boyle’s law, could be used to find one of the two variables at another pressure or temperature, given one of the variables and that the other conditions remain the same. Instead of using various solutions at different temperatures like in the experiment describe above, many experiments today utilize a solution in which the temperature is increased or decrease, such as in the following
Pressure relief valves are used to safely contain pressurized gases and liquids. Throughout the years there has been an increased demand for safety in industrial and other related operating practices. These valves are one of the many devices that have been created in conjunction with standardized design and operating practices, for the provision of this very protection. In the past, vessels that now would obviously require relief valves were heated often resulting in drastic increase in pressure within the vessel. This resulted in an extremely dangerous outcome physically for all the parties involved.
Background Knowledge -------------------- Pressure The three scientists Boyle, Amontons and Charles investigated the relationship between gas, volume and temperature. Boyle discovered that for a fixed mass of gas at constant temperature, the pressure is inversely proportional to its volume.
Pressure is defined as the force applied perpendicularly to the surface of an object per unit area over which that force is distributed. Pressure is a pushing force. Tension is a pulling force. What I have observed clinically is that increased fascial tension applies pressure on whatever lies beneath it as it pulls across the underlying structure. Because the fascial web is continuous from the feet to the head, and even inside the head, I have seen how increasing tension by dorsiflexing the foot, or pulling the toes towards the nose, can increase the pressure in a person’s head! Or, lifting their arm can increase the pressure in their head. What I see most commonly can best be illustrated by thinking about the body as if it is a rectangular
chamber used as a control will be used to measure any changes due to air
A Peak flow meter is a medical device that measures how well your lungs are able to expel air [2.1]. By blowing rough a mouthpiece a peak expiatory flow (PEF) reading can be found. This reading is measured in litres per minute and can be read directly from the device. When the person’s airways are more closed the lower the rate in which air can be blown out. The peak flow meters are used as a simple and efficient way of monitoring how well your lungs are and see if there functioning properly.
When the liquid level in both arms is the same, the pressure of the sample of gas inside the closed end must equal the pressure of the external atmosphere since the downward force on the two columns of liquid is then equal. When the liquid levels are unequal, the pressures must differ. The difference in pressure can be measured in units of length of the vertical column of liquid. The mm Hg, or its modern version the torr, originated in this use of the manometer. Mercury is particularly convenient for use in manometers (and barometers) because at room temperature it has low vapor pressure, does not wet glass, and has a high density. Other liquids such as linseed oil or water have also been used in manometers.
Generally pycnometer is made of glass, with a clos-fitting ground glass stopper with capillary tube through it, so that air bubbles mas escape from the apparatus. This device enables a liquid density to be measured through an appropriate working fluid, such as mercury or water, using analytical balance. When the flask weighed empty, full of water, and full of a liquid whose relative density is desired, then relative density can be easily calculated. The specific gravity results show that subsoil specific gravity varies between 2.45 and 2.7. Pycnometer analysis work system shown in Figure 12.
Before defining the term pressure cooker, we have to know, what is pressure? Pressure is the force acted per unit area exerted on a surface. In SI unit, it is measured in newton per square meter. It is called Pascal (Pa). The air pressure at the earth’s surface is due to the weight of the column of air above the surface (Kirkpatrick L.D 171)