The differences between the pressure sensor selection and the precision pressure switch

In the life, many people confuse sensors with the pressure sensor selection and the precision pressure switch. Indeed, both of them can be classified as sensors, but the functions and the information and security they provide are quite different. So what are the differences between them?

The precision pressure switch is absolutely the simpler and "old-fashioned" technology of the two. As the name implies, it is only a switch (contact or disconnection), which moves to one of two positions (open or close) through the pressure of the gas connected to it. It is not very precise (the range of specifications ranges from (+5%) to (+10%) of the full range), and the pressure setting is not highly repeatable. For example, the switch commonly used in our industry has a working pressure range of 0-3,200 psig with a full range accuracy/repeatability tolerance factor of 10%. Once set to a specific pressure (e.g. 1,200 psig), this means that the actual alarm condition may be triggered anywhere between 1,520 psig and 880 psig (3,200 = 10% = 320 1,200 + 320 = 1,520 1,200 - 320 = 880) and each time an alarm can occur under different pressures within this range. Another disadvantage of pressure switches is that the only way to know whether the switch is working properly is to test it. This requires that precision pressure switch be physically disconnected from the pipeline so that the pressure is lower than the low-voltage alarm setting point. If the high/low switch is connected to the pump, the pressure is raised to t above the high-voltage setting point. Such testing must be done manually, usually only during periodic (in most cases annual) inspections. The differences between the pressure sensor selection and the precision pressure switch

The pressure sensor selections are more complex "new school" technologies and are the choice of more and more manufacturers, replacing pressure switches. How do they work? Like pressure switches, transducers are connected to medical gas pipes. Gas pressure has nothing to do with metal (usually stainless steel) diaphragms, which deflect or bend according to the rise and fall of gas pressure. The deflection is measured by a transducer, and the information is transmitted to the circuit board in millivolts. It should be noted that all sensors must work with the circuit board. Most manufacturers build sensors on related circuit boards, so information is transmitted in millivolt format at a distance of a fraction of an inch. Then the information is digitized by the circuit board and transmitted to remote logic boards (such as area alarms or manifolds), which contain digital pressures and LED displays that hospital staff usually view. The pressure sensor selection is very accurate (within 3% of the full range) and highly repeatable (within 1 psig). Obviously, only these factors provide additional safety and precision pressure switch. In addition, as the pressure sensor selections works within the normal millivolt output range, manufacturers can easily build additional security functions for their related circuits and logic boards, which can trigger or display alarm conditions or warnings immediately within the normal millivolt output range when the pressure sensor selections is not working. Essentially, the pressure sensor selections are tested many times a second - not only periodically, but annually.

In a fast and changing electronic world, the cost of the pressure sensor selections has become more affordable. When you compare sensors with pressure switches, the pressure sensor selections inherently provide functions and advantages that pressure switches do not have: The pressure sensor selections are more accurate
  
The pressure sensor selections provide digital pressure display
The pressure sensor selections provide higher repeatability
The cost of the pressure sensor selections are cheaper in many cases.
The pressure sensor selections can be used in conjunction with logic boards to provide higher security

That's why the design of the Tri-Tech Medical Regional Alarm and Digital Manifold of the United States uses the pressure sensor selections instead of the precision pressure switch.