Tag: Sensors
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The Construction & Principle of Operation of Load Cells
A load cell converts a force (usually the gravitation force from an object being weighed) to a strain which can then be converted to an electrical signal by strain gauges. A load cell will typically have a local circuit as illustrated in figure 1(a) with four gauges; two in compression and two in tension and…
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The Conditioning of Thermocouple Sensor Voltages
Consider the circuit below: From the figure above, the sensing junction and reference junction are connected in series. When the junctions are at the same temperature the voltage output from the junctions is zero and the output from the amplifier is zero. When the junctions are at different temperatures, there is a differential voltage at…
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RTD 2, 3, 4 Wire Sensor Connections
The resistance temperature devices (RTD) can be connected directly to the controller peripheral amplifiers using 2-wire, 3-wire or 4-wire lead configuration. The wires in all these connections are in shielded cables. The RTD is usually driven from a constant current source (I) and the voltage drop (V) across the RTD is measured. RTD 2-wire connection…
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Instrumentation Sensors and Transducers – Multiple Choice Questions & Answers (MCQ4)
The Answers have been provided at the end of the Questions: Q1. Which of the following sensors is used to measure displacement? A. Thermistor B. LVDT C. Dall tube D. None of the above Q2. Which of the below listed sensors is used for temperature measurement? A. Strain gauge B. Thermistor C. Piezoelectric crystal D.…
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Types of Sensors used in Measurement and Process Control
A sensor is an element in a measurement system that detects the magnitude of a physical variable or parameter and changes it into a signal that can be processed by the system. The active element of a sensor is often referred to as a transducer. The monitoring and control systems require sensors to measure physical…