Alarm Annunciator Circuit with Acknowledge
Explain how the following annunciator circuit works: Note the jumper options shown in the diagram: one set of jumper positions configures the alarm for a process switch that alarms when…
Identify Process Variables in P&ID
Identify Process Variables in P&ID as they apply to the level controller shown in this P&ID (LIC 135), controlling the level of liquid in the horizontal receiver vessel: Process Variable…
Why it is important to note As-Found and As-Left data during Calibration?
An instrument technician working for a pharmaceutical processing company is given the task of calibrating a temperature recording device used to display and log the temperature of a critical batch…
Single Loop Controller Questions
A simple diagram is shown here, where a single loop controller controls the speed of a DC electric motor using the concept of feedback control. Single Loop Controller The motor…
Diagnosing Electric Motor Circuit
Suppose the electric motor refuses to run when the “Run” pushbutton switch is pressed. A technician begins diagnosing electric motor circuit following the steps shown (in order): Test 1: Measured 12…
Gas Compressor Seal Oil System
Spending a fortune to buy the state of the art machinery is no big deal when compared to the headaches that follow due to bad maintenance of gas compressors. The…
Questions on Pneumatic Control Loop
Examine these two pneumatic control loops (transmitter-controller-valve systems) for an industrial boiler, controlling both water level and steam pressure: Pneumatic Control Loop If the PIC setpoint is 225 PSI and…
Identify Instrumentation Terms in Water Supply System
You have to Identify Instrumentation Terms in Water Supply System in this example problem. A water reservoir located high on a hill stores fresh water for a town’s drinking needs.…
Cut-outs between Platforms or Grating for Field Instruments
Usually, Cut-outs between platforms or grating are not given due importance as they can be done on-site. While we have such an approach, there is a concern that could go…
Difference between Axial and Radial Diaphragm Seal Connection?
The basics:- What is the difference between Axial and Radial movement mean? Axial movement Imagine a circle and you are in the middle of the circle. Now you start jumping, this…
