The measurement of a given quantity is essentially an act or result of comparison between a quantity, whose magnitude (amount) is unknown with a similar quantity whose magnitude (amount) is known, the latter being called standard. Measurement involves the use of the instrument as a physical means of determining quantities or variables. The instruments serve … Read moreMeasurement Systems | Functions & Applications
An Instrument may be defined as a device or a system which is designed to maintain a functional relationship between prescribed properties of physical variables and must include ways and means of communication to a human observer. Functional Elements of an Instrumentation System Most of the measurement system contains following main functional elements as shown … Read moreFunctional Elements of an Instrumentation System
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 an input signal or the quantity being measured. The reciprocal of sensitivity is defined as inverse sensitivity or deflection factor. The sensitivity of an instrument should … Read moreStatic Sensitivity, Linearity and Hysteresis
In this article, we will see the difference between accuracy and precision terms. They are also most confusing terms in measurements regarding instruments. Accuracy Accuracy is the closeness with which the instrument reading reaches the true value of the quantity being measured. The accuracy of measurement means conformity to truth. The accuracy can be … Read moreAccuracy and Precision
Scale Range and Scale Span are two most confusing terms in measurement. Many a times students get confused with these two terms. Here I have clarified both these terms in the easy language. In analog instruments, the value of measurand is indicated by the pointer on a scale. A scale has some values mentioned on … Read moreScale Range and Scale Span
In this article, we will learn about two important terms Reproducibility and Drift. These two terms are important for instruments in measurements. Reproducibility Reproducibility is defined as the degree of closeness with which a given value may be repeatedly measured. Drift Drift is the gradual shift in the indication or record of the instrument over … Read moreReproducibility, Drift and Repeatability
In this article, we will understand the concept of errors in measurement, types of errors in measurement in detail. This is most important and starting topic in measurements. True Value It is defined as the average value of an infinite number of measured values when average deviation due to various contributing factor approaches to zero. It … Read moreErrors in Measurement and Types of Errors
Data loggers are nowadays used by Environmental consultants, energy auditors, building managers, research scientists, engineers for recording data in many applications. We will know in detail about data loggers, its anatomy, working principle, advantages and applications. Data Logger It is an electronic instrument that records measurements at set intervals over a period of time. Data loggers … Read moreWhat are Data Loggers | Advantages & Applications
Resistance Temperature Detector (RTD) It is a device which senses the resistance change on account of temperature change. This property is used for measurement of temperature. Resistance Temperature Detector (RTD) is also called as a resistance thermometer. It uses the change in electrical resistance to measure the temperature. Construction of RTD RTD elements consist of … Read moreResistance Temperature Detector (RTD) or Resistance Thermometers
Fig. NTC Thermistors (source: ussensor.com) Thermistors These are the thermally sensitive resistors. The resistance of a thermistor varies as a function of temperature. The thermistor is also called thermal resistors. It is a resistive temperature transducer. Thermistors are composed of semiconductor materials. It is composed of a sintered mixture of metallic oxides such as Mn, … Read moreThermistors Characteristics | Advantages & Applications