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, recording, integrating a quantity at … Read more
In this article, we will learn about different test parameters that are required after performing medical tests on patients to analyse statistical data. We may define terms for test results 1. True positive (TP): A true positive test result is one that detects the condition when the condition is present. TP denotes the number of true … Read more
Fig. Capacitive transducers (source: directindustry.com) Capacitive Transducers The capacitive transducer is the capacitor with variable capacitance. The capacitive transducer consists of two parallel metal plates that are separated by the dielectric material such as air. We are familiar with the equation of capacitor which is given as In a normal capacitor, the … Read more
What is an analog-to-digital converter? An analog-to-digital converter (ADC) is a system that converts an analog signal to a digital signal. For example, a sound picked up by a microphone into a digital signal. The output of a microphone, the voltage at a photodiode or the signal of an accelerometer are the examples of the … Read more
Figure. RVDT In the 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 the angular displacement … Read more
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 of input quantity for which … Read more
The basic difference between Analog & Digital Instrument is given below. S.No. Aspects Analog Instrument Digital Instrument 1. Information form As the position of pointer on a dial/scale As a number 2. Possibility of human error Exists Does not exist 3. Best possible accuracy 0.25% +0.005% or greater 4. Resolution one in several hundreds one part in … Read more
In Inductive transducers, the basic principle is that self-inductance of a single coil or the mutual inductance between two coils is changed by a quantity to be measured i.e. measurand. Usually, the measurand could be a rotary or linear displacement, force, pressure, torque, velocity, acceleration, and vibration. For example, LVDT is an inductive transducer which … Read more
A sensor is basically a device that converts the physical parameter (for example, viscosity, temperature, blood pressure, light intensity, humidity, speed, etc.) into a signal(may be electrical or non-electrical quantity) which can be easily measured. For example, let us consider an electrical resistance temperature element. Here the measurand is the temperature which is being sensed … Read more
What is Ultrasound? Ultrasound or ultrasonography is a medical imaging technique that uses high-frequency sound waves and their echoes to create images of the inside of the body. This technique is similar to the SONAR used by submarines, echolocation used by bats, dolphins, and whales. How Ultrasound Creates an Image A gel is applied to the body area which … Read more