What is Keyphasor ? How does Keyphasor works ?
A transducer that produces a voltage pulse for each turn of the shaft, called the Keyphasor. This keyphasor signal is used primarily to measure rotating shaft speed and serves as…
Proximity Transducer System Operation
Proximity Transducer System provides an output voltage directly proportional to the distance between the probe tip and the observed conductive surface. It is capable of both static (position) and dynamic (vibration) measurements, and…
Objective Questions on Valves
List of Objective Questions on Valves, Valves Test Questions and Online Quiz on Control Valves. Test Your skills on Control Valves. Objective Questions on Valves Valves Objective Questions 1. Valves are defined…
What is Process Override Switch (POS)?
Process Override Switch shall be provided to override unhealthy field inputs in order to facilitate start-up, which shall automatically be released upon normalisation of the field input or preset time,…
What is Maintenance Override Switch (MOS) ?
Maintenance Override Switch (MOS) shall be provided to override all field inputs designated to trip the facility in order to facilitate maintenance of field devices without interrupting the plant operation.…
Foundation Fieldbus Split Range Valves
In FOUNDATION Fieldbus systems (Note1), where a special software function block called “SPLT” exists to provide split-ranged sequencing to two valves. The “SPLT” function block takes in a single control…
Emergency Shutdown System Philosophy
The Emergency Shutdown System (ESD) is designed to protect the personnel, plant, equipment and the environment against pollution. The purpose of the ESD system is to monitor process safety parameters…
How to Read Circular Chart Recorder for Flow Measurement?
Flow Transmitter output in square-root value and chart recorder prints flow value in range 0 to 100%. How to read circular chart recorder?
PLC Ladder Logic for Start-up Control of Boilers
The start-up control for the boilers is enabled via a master thermostat. PLC control is to be used to ensure that 4 gas boilers do not start up simultaneously in…
Difference between Fieldbus, Profibus and HART Protocols
The method of representing, encoding, and transmitting the data is called the protocol. At the field level, the dominant protocols for process instruments are HART, FOUNDATION Fieldbus H1 and PROFIBUS…
