Why RTD installed after the Orifice Plate ?
Why RTD installed after the Orifice Plate ? The location of the RTD (thermowell), positioned downstream of the orifice plate so the turbulence it generates will not create additional turbulence…
What is Emergency Shutdown System (ESD) ?
A critical condition for which immediate shutdown of the gas turbine and compressor is required and delayed shutdown options are not acceptable because of the danger posed to the compressor…
Functions of Pressure Detectors
Pressure Detector Functions Although the pressures that are monitored vary slightly depending on the details of facility design, all pressure detectors are used to provide up to three basic functions:…
Functions of Temperature Detectors
Functions of Temperature Detectors Although the temperatures that are monitored vary slightly depending on the details of facility design, temperature detectors are used to provide three basic functions: indication, alarm,…
Resistance Type Pressure Transducers Principle
Resistance-Type Pressure Transducers Included in this category of transducers are strain gauges and moving contacts (slidewire variable resistors). Figure 1 illustrates a simple strain gauge. A strain gauge measures the…
Inductance Type Pressure Transducers Principle
The inductance-type transducer consists of three parts: a coil, a movable magnetic core, and a pressure sensing element. The element is attached to the core, and, as pressure varies, the…
Capacitive Type Pressure Transducers Principle
Capacitive-type transducers, illustrated in Figure, consist of two flexible conductive plates and a dielectric. In this case, the dielectric is the fluid. As pressure increases, the flexible conductive plates will…
Bridge Circuit Construction
Figure 1 shows a basic bridge circuit which consists of three known resistances, R1, R2, and R3 (variable), an unknown variable resistor RX (RTD), a source of voltage, and a…
Thermocouple Construction
A thermocouple is constructed of two dissimilar metal wires joined at one end. When one end of each wire is connected to a measuring instrument, the thermocouple becomes a sensitive…
Resistance Temperature Detectors (RTD) Construction
The RTD incorporates pure metals or certain alloys that increase in resistance as temperature increases and, conversely, decrease in resistance as temperature decreases. RTDs act somewhat like an electrical transducer,…
