JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV SENSORS AND TRANSDUCERS Previous Question Paper (December - 2020 - R16)

A measurement system is designed to convert a physical quantity into a measurable output. It consists of three primary functional elements: the primary sensing element, the variable conversion element, and the data presentation element.

1. Primary Sensing Element: This element is in direct contact with the physical quantity (measurand) being measured. It detects the change in the physical variable and produces an output that is a function of the measurand. Its significance lies in its ability to initiate the measurement process by converting the physical parameter into a usable form, such as mechanical displacement or electrical resistance change.

2. Variable Conversion Element: The output of the primary sensing element may not be in a form suitable for further processing or display. The variable conversion element converts this signal into a more convenient variable, typically an electrical signal like voltage or current. This is significant because electrical signals are easier to amplify, filter, transmit, and process using modern electronic circuitry.

3. Data Presentation Element: This element provides the final information to the user in a readable format. It may consist of a display device, a recorder, or a data storage unit. Its significance is to communicate the magnitude of the measured quantity to the observer or to a control system, allowing for monitoring, analysis, or automated decision-making.

In many systems, additional elements like signal conditioning (amplification, filtering) and data transmission are integrated between these stages to ensure accuracy, sensitivity, and reliability of the measurement.