Functional Safety Questions & Answers

Functional Safety Questions & Answers : SIS as an "instrumented system used to implement one or more safety instrumented functions. Functional Safety Questions & Answers What is PHA ? Process…

Types of Valve Leakage Tests

All valves are inspected and tested by the manufacturer to ensure that they conform to the required valve leakage standards. In addition, optional testing can be requested by the purchaser,…

How to Connect Proximity Switch (Source Type) to Make LED ON ?

An improvement over direct-contact limit switches for many applications is the inductive proximity switch. This type of switch actuates simply when an object gets near it – no direct physical…

Define Normal Status of a Process Switch ?

Switches, whether they be hand-actuated or actuated by a physical process, come in two varieties: normally-open (NO) and normally-closed (NC). You are probably accustomed to seeing both types of switch…

Breather Valve Working Principle

Breather Valve, also known as direct acting Pressure/Vacuum Relief Valves, are special types of Relief Valves which are specifically designed for tank protection. The range includes pressure only, vacuum only…

Strip Chart Recorder Working Principle

A chart recorder is an instrument used to record various process and electrical signals. The most traditional chart recorders record data on paper. The paper is passed under a pen and the…

What is a Control Loop ?

A control loop is a process management system designed to maintain a process variable at a desired set point. Each step in the loop works in conjunction with the others…

80+ Flow Measurement Interview Questions and Answers

Flow Measurement Interview Questions: Preparing for a Field Instrumentation Interview then read this article about flow measurement and test yourself.

What is a Hydraulic Actuator ?

Pneumatic actuators are normally used to control processes requiring quick and accurate response, as they do not require a large amount of motive force. However, when a large amount of…

Relay circuits

Relays may be connected together to perform logic and control functions, acting as logic elements much like digital gates (AND, OR, etc.).