What Is a Pressure Transmitter?
A pressure transmitter is a device that transmits pressure. The difference between a pressure transmitter and a pressure gauge is that a pressure gauge only displays pressure on site and requires actual visual observation. Whereas, a pressure transmitter transmits pressure as an electrical signal, allowing pressure monitoring from a remote location.
Of course, it is also possible to check the pressure on site by combining it with a digital display.
In today’s world of factory automation, control and alarms through automatic pressure monitoring are indispensable to save labor. Therefore, pressure transmitters are indispensable.
Uses of Pressure Transmitters
Pressure transmitters are installed where pressure monitoring is required.
For example, they are used to control tanks that hold high pressure or control valves that regulate pressure.
Pressure transmitters can also be used to control pressure since the current pressure can be constantly displayed via an electrical signal. Especially in pressure tanks, where an increase in pressure can lead to a major accident. Pressure transmitters are sometimes used to stop the equipment by issuing an alarm before a safety valve or similar device is commonly used.
Principle of Pressure Transmitters
The structure of a pressure transmitter is very different from that of a pressure gauge. At first glance, a pressure transmitter looks like a simple cylindrical device, but it has a membrane called a diaphragm attached to its tip, and a strain gage is attached to the diaphragm to convert the deformation of the diaphragm into pressure.
Basically, the diaphragm is made of stainless steel, such as SUS304, which is highly durable. Also, by changing the material of the diaphragm, it is possible to accommodate a wide variety of process fluids.
Furthermore, the strain gauge converts the signal of diaphragm deformation into pressure and outputs it as a 4-20mA analog signal, making it possible to measure continuous changes in pressure.
It is important to note that pressure transmitters are standardized in terms of pressure range, depending on the pressure to be used.
In particular, if the pressure transmitter cannot measure vacuum, it will only display “0” no matter how much vacuum is generated.
Software must also be created to ensure that if a pressure transmitter malfunctions or disconnects, the equipment will not go in a dangerous direction.