Often when solving problems in the field of physics, one has to deal with such devices as manometers. But what is a pressure gauge, how does it work and what kinds are there? About this and talk today.
This device is designed to measureoverpressure. However, the pressure may be different, and therefore different pressure gauges exist. For example, to measure atmospheric pressure, vacuum gauges are used, differential pressure gauges are used to determine the differential pressure. But in any case they measure only the pressure.
It is impossible to describe all areas nowthe use of these devices, because they are very many. They can be used in the automotive industry, in agriculture, communal and housing, in any mechanical transport, metallurgical industry, etc. Depending on the purpose, there are different types of meter data, but their essence is always reduced to one - to the measurement of pressure.
Also these devices are divided into different groups independence on the principle of measurement. Now, when it is more or less clear what a pressure gauge is, you can move on to details. In particular, we will describe the types and areas of their application.
Depending on the intended use, pressure gauges maybe of different kinds. For example, liquid manometers are used to measure the pressure of a liquid column. There are spring devices capable of measuring the applied force. Here, the pressure is measured by equilibration with the force of the spring deformation.
Less popular are piston pressure gauges, where the measured pressure is counterbalanced by the force that acts on the piston of the device.
Also note that, depending on the purpose and conditions of use, the following devices are manufactured:
Also, these devices can be divided intosensitivity of the element, accuracy classes. For example, according to accuracy classes, manometers are: 0.15, 0.25, 0.4, 0.6, 1, 1.5, 2.5, 4. Here the number determines the accuracy of the device, and the lower it is, the better the device.
These pressure gauges are intended for measurementoverpressure. Their measurement principle is based on the use of a special spring, which deforms under the influence of pressure. The value of the deformation of the sensing element (spring) is determined by a special reading device, which, in turn, has a graduated scale. On this scale, the user sees the value of the measured pressure.
The sensitive element in such pressure gauges is oftenThe so-called Bourdon tube - a sensitive single-turn spring acts in all. However, there are other elements: flat corrugated membrane, multi-turn tubular spring, bellows (harmonica-shaped membrane). All of them are equally effective, but the most simple and affordable, and because of this, the most common is a pressure gauge that shows the pressure with a single-turn Bourdon spring. It is these models that are actively used to measure pressure in the range of 0.6-1600 kgf / cm2.
Unlike spring ones, in liquid manometersThe pressure is measured by balancing the weight of the liquid column, and the pressure measure in this case is the fluid level in the communicating vessels. Such devices allow measuring pressure in the range of 10-105 Pa, and they are used mainly in laboratory conditions.
In fact, such a device is a U-shaped tube withliquid with a large specific gravity in comparison with the liquid directly in which the hydrostatic pressure is measured. Most often, such a liquid is mercury.
In this category, indirectlygeneral technical and working instruments such as a manometer TM-510, TV-510, which are the most popular category. They measure the pressure of non-crystallizing and non-corrosive fumes and gases. The accuracy class of such pressure gauges is 1, 2.5, 1.5. They are used in boiler houses, in heat supply systems, in the transportation of liquids, and in production processes.
This category includes vacuum metersand manometers. They are designed to measure the pressure of liquids and gases that are neutral with respect to steel and brass. The design of these devices is similar to spring, but the difference is only in large geometric dimensions. The body of the electrocontact manometer is large due to the arrangement of the contact groups. Also, such a device can act on the pressure in the controlled environment due to the closing / opening of the contacts.
Thanks to the special electro-contact mechanism, which is used here, the device can be used in an alarm system. Actually, in this area it is also used.
This type of instrument is designed to testmanometers used for measurements in the laboratory. Their main purpose is to check the correctness of the readings of working manometers. A distinctive feature of such devices is a very high class of accuracy, which is achieved due to design features, as well as gearing in the gear mechanism.
This category of devices is used in differentindustries to measure the pressure of gases such as ammonia, hydrogen, oxygen, acetylene, etc. The most common measurement of a special manometer is only one type of gas. For each such manometer, the type of gas is indicated, for the measurement of the pressure of which it is intended. Also, the gauge itself is painted in a certain color, corresponding to the color of the gas for which this device is intended. In the designation of the device, a certain letter is also used. For example, ammonia gauges are always painted in yellow, denoted by letter A and have a corrosion-resistant design.
There are special vibration-proof devices,They operate under conditions of high pulsating pressure of the environment and strong vibrations. If in such conditions to use a conventional manometer, then it will not last long, because the transmission mechanism will quickly fail. The main criterion of a vibration-proof manometer is the tightness and corrosion-resistant steel of the body.
The main difference between these gauges follows fromtitle. These devices continuously record the measured pressure in the diagram, which later allows you to see the graph of pressure changes in a certain time interval. Such devices are used in power engineering and industry to measure the production of indicators in non-aggressive environments.
These are intended to measurevacuum pressure of gases, vapor and liquids (oil, diesel, water). Such devices are characterized by higher water resistance, resistance to climatic influences and vibrations. Based on the name, you can understand their scope - river and sea transport.
Unlike conventional manometers showingthe pressure value, the railway instruments do not show, but convert the pressure into a signal of another kind (digital, pneumatic, etc.). Various methods can be used for this.
Such pressure transducers are activeThey are used in process control systems, automatics and, despite their direct name, they are used in the oil production, chemical and nuclear power industries.
Pressure measurement is required in many industries,and for each of them there are special gauges with their unique features. There are even special reference gauges, which are intended for tuning and mandatory checking of working instruments. They are stored in Rostekhnadzor.
But in any industry and any type of these devicesis intended for measuring only pressure. Now you know what a pressure gauge is, what kinds of things happen and how you understand the principle of measuring pressure.
