# Instrumentation

## Analog to Digital Conversion

Analog to Digital Conversion Physical quantities like temperature, pressure, velocity etc. can be measured using transducer circuits. The resulting analog voltage produced by a transducer is often converted to digital form so that it can be processed by a computer or a digital signal processor (DSP). The conversion of an analog signal to digital utilizes […]

## Method of Measuring Displacement, Velocity and Acceleration

Method of Measuring Displacement, Velocity and Acceleration Displacement is a quantity that indicates the change in position of a body or point. Angular displacement refers to a rotation that can be measured in degrees or radians. Displacement transducers can be either contacting or noncontacting. Contacting transducers typically use a sensing shaft with a coupling device

## Method of Measuring Strain, Pressure, and Flow Rate

Method of Measuring Strain, Pressure, and Flow Rate Strain is the deformation, either expansion or compression, of a material due to a force acting on it. For example, a metal rod or bar will lengthen slightly when an appropriate force is applied, as illustrated in Figure 1(a). Also, if a metal plate is bent, there

## Methods of Measuring Temperature

Methods of Measuring Temperature Temperature is the most common physical parameter that is measured and converted to electrical form. Several types of temperature transducers respond to temperature and produce a corresponding indication by a change or alteration in a physical characteristic that can be detected by an electronic circuit. Common types of temperature transducers are

## Applications of Wheatstone Bridge

Applications of Wheatstone Bridge The Wheatstone bridge circuit can be used to precisely measure resistance. However, the bridge is most commonly used in conjunction with transducers to measure physical quantities such as strain, temperature, and pressure. Transducers are devices that sense a change in a physical parameter and convert that change into an electrical quantity

## Function of Encoder, Decoder & Multiplexer

Function of Encoder An encoder is a combinational logic circuit that accepts one or more inputs and generates a multibit binary output. Encoding is the process of converting any keyboard character or number as input to a coded output such as a binary or BCD form. Figure 1 shows a decimal-to-binary encoder. Its function is

## Signal Conditioning by Filter Circuits

In many situations, the raw output of the sensor may not be in a form suitable to be interfaced to a measurement device or an A/D convertor, and some form of signal conditioning is needed to be applied to the sensor output. These signal conditioning operations include filtering, amplification, or using a bridge circuit. In

## Characteristics of Sensors

There are a number of parameters that characterize sensors’ performance. The time-independent characteristics are called the static characteristics, while the time-dependent characteristics are called the dynamic characteristics. The static characteristics characterize the sensor output after it has settled due to changes in the physical quantity being measured. The dynamic characteristics describe the sensor characteristics from

## Distinctive Thermocouple Noise Problems

Distinctive Thermocouple Noise Problems Thermocouple emfs are small. Fine temperature resolution requires substantial amplification. For quasi-static thermometry, modern noise suppression techniques available to designers of data loggers overcome ordinary coupled electrical noise to routinely achieve as small as 0.1 °C temperature resolution and long-term stability (much smaller than required by thermocouple tolerance). Thermocouple measurement of

## Thermocouple Thermometry Practice

Thermocouple Thermometry Practice Temperature Ranges Moderate and High Temperatures: Temperature and duration of exposure are unavoidable environmental variables in thermometry. Other environments can sometimes be controlled. Standard thermocouple tables extend only to the greatest temperature of recommended use for benign protected environments, short durations, and for wire materials of 3 mm or greater diameter. Reduced