Gauge (electric) is an electric sensor alarm maximum and minimum pressure, which is intended to measure. Performs such work built-in alarm device, consisting of two simple arrows, set the maximum and minimum value determined by the pressure and contact by the measuring pointer.

## Device description

This setup looks like an ordinary device in which the measured value is the pressure. In addition to this indicator, electric contact pressure gauge control has two electrical contacts. Test signs installed in the designated position on the high and the low with two heads displayed outside through the glass and located above the rotation line defining the arrow, which is due to its limits closes the connection electric circuit, a transmitting signal.

Electric contact gauge EKM is considered mechanical and is used to measure excessive pressure of water, oils, emulsions, vapors and various gases with volume of up to several tens and hundreds of atmospheres. There are 3 pressure class:

## Atmospheric

It is the pressure of the air mass the earth's environment to the sphere of the earth and all that therein is. Such pressure is present constantly and everywhere, but people can't feel it. The pressure of the atmosphere changes all the time.

## Excess

It is the pressure conditions (gas, water, steam and so on) in the inner part of the pipeline. If the water pressure is greater than atmospheric, then the pipeline to contain the pressure. But if the pressure in the water less air, so the atmosphere inside it is exhausted, and will witness the pressure gauge (electric).

## Absolute

Is the number of atmospheric and gauge pressure in the pipeline. The device is designed for determining the absolute pressure when the pressure in the water equals the air, approximately equal to 100 kPa. If the internal part of the pipe, the atmosphere is discharged, the pressure gauges tend to 0.

## It is important to know

1. Quite often the housing device intended for measuring pressure of gases, paint in various shades. So, equipment with a blue color shell is used to determine the pressure of oxygen. The yellow tone of the case has electrocontact pressure gauge for ammonia, white – acetylene, grey – chlorine, and dark green – hydrogen. Appliances on propane and other combustible gases are characterized by red color. The black shade have settings that are essential for the functioning of the non-combustible gas.
2. Oxygen equipment in any case, it should be degreased, as sometimes even a small blockage of the connecting sleeve and the device in contact with rich oxygen can lead to fire and even worse – explosion. Installation on acetylene does not presuppose the presence in the mechanism of measurement of alloys of copper, because when connecting with this element there is a risk of an explosive mixture.
3. The same pressure gauge (electric) can be used to determine the pressure at different conditions (gas, liquid, steam) if the foundations of his devices resistant to these environments. If the device has limited use, its scale, there are additional signs that tell about the properties of the operation of such a facility.
4. The red mark applied to the device glass corresponds to the ultimate pressure of the measured conditions or to the working pressure of the container, depending on the area of ​​application of the pressure gauge.
5. Normally maintenance of equipment (replacement, installation, removal) produce plumbers, gas or other production staff (operatives). To check, for example, electric contact pressure gauge DM, used oil column. On safety rules in addition to the annual testing, the device must additionally be checked by means of the control device.

## The principle of operation

The plant is operated thus: the pressure medium through the connecting sleeve is in the inner part of the bent copper pipes of oval section. Under the influence of this pressure the hose lining trying. The movement of the pipe occurs on a spring-loaded rod with a indicator through the balance and severity. Needle rotates following the movement of the hose, exposing the incoming pressure.

The measuring system is contained within the housing with a scale. The shell of the equipment to determine the water pressure, frequently produce sealed and further filled with glycerin to suppress water hammer, and decreasing tremor (shaking) of the pointer. To reduce the effect of such attacks on the devices, it connects to the damping tube Perkins. For protection of the device against surges of pressure can be similarly applied to a push-button valve. In this case, the pressure gauge (electric) shows the value of the working pressure with a push of a button on the valve.