Voltage Telemetry System
A voltage telemetry system transmits the measured variable as a function of AC or DC voltage. A slide wire potentiometer is connected in series with the battery. The signal transmitting medium is essentially a copper wire line. The sliding contact is positioned by a pressure sensitive, Bourdon tube. The telemetric…
Telemetry Systems
In modern measurement systems, the various components comprising the system are usually located at the distance from each other. It is, therefore, becomes necessary to transmit the data and information between them through some form of communication channel. Telemetry may be defined as measurement at a distance. Telemetry is indicating,…
Magnetostriction & Villari Effect
Magnetostriction When a material (magnetic material) is magnetised, changes in dimension are generally observed. This property of a magnetic material is called magnetostriction. There are three types of Magnetostriction Longitudinal Transverse Volume 1. Longitudinal Magnetostriction When a change in the dimension is in the direction of applied field. 2. Transverse Magnetostriction When a change…
Difference Between CT and PT
S.No. Current Transformer (CT) Potential Transformer (PT) 1. It is connected in series with the power circuit. It is connected in parallel with the power circuit. 2. Its secondary is connected to an Ammeter. Its secondary is connected to a Voltmeter. 3. Its secondary work always in short circuit…
Resolvers Working Principle & Applications
Resolver source: designworldonline.com Resolver is a synchro whose rotor is mechanically driven to translate rotor angle into electrical information corresponding to the sine and cosine of rotor angle. It can interchange rectangular and polar coordinates. It is also called a sine-cosine generator and synchro-resolver. It is an analog device. A…
Static Sensitivity, Linearity and Hysteresis
Static Sensitivity Static Sensitivity of an instrument or an instrumentation system is defined as the ratio of the magnitude of the output signal or response to the magnitude of input signal or the quantity being measured. The reciprocal of sensitivity is defined as inverse sensitivity or deflection factor. The sensitivity…
Rotary Variable Differential Transformer (RVDT) Working Principle & Applications
Figure. RVDT In previous article, we have learned about Linear variable differential transformer (LVDT). Rotary Variable Differential Transformer (RVDT) is a variation of LVDT and used to sense angular displacement. It is a passive transducer. In short, RVDT provides a variable alternating current (AC) output voltage that is linearly proportional to…
Linear Variable Differential Transformer (LVDT) Working Principle & Applications
Fig: LVDT cross-section (source: te.com ) Linear Variable Differential Transformer (LVDT) is an inductive transducer that we discussed in previous article. It is basically used to translate linear motion into electrical signals. LVDT Construction LVDT consists of one primary winding and two secondary windings. All these windings are wound on…
Dead Time, Dead Zone and Resolution
Dead Time It is defined as the time required by a measurement system to begin to respond to a change in the measurand. It is basically the time before the instrument begins to respond after the measurand has been changed. Dead Zone Dead zone is defined as the largest change…
Hall Effect Transducers Working Transducers & Applications
Hall Effect Transducers are the transducers which works on the principle of hall effect. According to hall effect, if a conducting material strip carries current in the presence of a transverse magnetic field; an EMF is produced between two edges of conductor in a direction perpendicular to both the magnetic…