Use Of HVAC Pressure Sensors For Checking Air Flow And Others
This article looks at the various applications of HVAC pressure sensors, such as the monitoring of the differential pressure of air flow in air conditioned rooms. These are examples of sensors or transducers that are capable of detecting low pressures. These devices can be utilized for monitoring the differential air pressures in factories, in the HVAC duct of a building, pharmaceutical laboratories, and clean rooms for semiconductor processing. Oftentimes, this is a differential pressure transmitter that can measure minuscule movements of the sensing diaphragm. One way to allow this is through the application of inductive coupling technology. This type of sensing technology in HVAC pressure sensors offers a consistent and very stable technique for detecting low pressures.
The differential pressure sensor for use as one of the HVAC pressure sensors can be designed to be capable sensing pressures as low as 10 pascals or approximately 0.00145 psi. This has a wide range of uses, such as determining the condition of an air filter by measuring the difference in pressure before and after the filter. It can also be utilized for determining the difference between the air pressure at the entry point of a ventilation duct and at its exit point. And if there is a need for a local display of the pressure reading, an LCD or LED display can be installed as part of the system. HVAC applications for these sensors include static duct pressure monitoring, variable air volume systems, detection of gaseous leak, modulated furnace controls, combustion air flow, and monitoring of the filter pressure. In refrigeration, these devices can be utilized in the monitoring of refrigerant suction and discharge, chillers, monitoring of refrigerant suction and then discharge, steam recovery, and hydronic systems.
These pressure sensors may also find applications in refrigeration where there are special design issues to be resolved. First of all, these detectors should not have any internal gaskets or seals because pressure sensors with O-rings are unable to handle the very fast thermal changes that are possible with ammonia-based refrigeration and HVAC systems. Sensor devices containing fluids cannot also be utilized for such cold systems because they tend to freeze and this can damage the diaphragm membrane. Special designs that do not have O-rings or fluids are required to handle quick thermal changes.
HVAC pressure sensors may also find application in monitoring systems for vehicle tire pressure. Such a system is made up of a tire pressure sensor, a transmitter, a controller, and various displays. Constant checking of the tire pressure is important because an under-inflated tire results in faster tire wear, a reduction in gas mileage, and heightened rolling resistance. An under-inflated vehicle tire is also unsafe because it could produce heat and the temperature could reach the level where a blowout may occur. There are various applications for this kind of pressure sensors and there are also different kinds of designs. For example, these sensors can use a piezoresistive sense element that is provided with oil or capacitive or capacitive ceramic microelectromechanical systems.
