Introduction-
An optical sensor is a device that converts light rays into electronic signals. It measures the physical quantity of light and translates it into a form read by the instrument.
One of the features of an optical sensor is its ability to measure the changes from one or more light beams. This change is mostly based on the alteration of the light’s intensity. Optical sensors can work either on single point method or through a distribution of points. The major importance to the proper use of an optical sensor is that it retains certain facets of measured properties. It must always remain sensitive to the property.
Optical Sensors are used in numerous research, and commercial applications such as for quality and process control, medico technologies, metrology, imaging, and remote sensing.
Advantages and disadvantages-
Some of the significant advantages of optical sensors as compared to conventional (or, non-optical) sensors are: greater sensitivity, electrical indifference, freedom from electromagnetic interference, wide dynamic range, both point and distributed configuration and its multiplexing capabilities.
A difficulty of all sensors, both optical and non-optical, is interference from multiple effects. A sensor intended to measure strain or pressure may be very temperature-sensitive.
Measurands-
Almost all of the physical measurands can be measured, and some of the measurands possible through optical sensors are: temperature, pressure, flow, displacement, vibration, rotation, magnetic fields, acceleration, force, humidity, strain, velocity, pH, electric fields, radiation, and chemical species.
Principle of operation-
Optical sensors incorporate an infra-red transmitter and receiver device housed in a si...
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...uodenum, etc., and dentistry for contact probes to measure blood flow in the teeth and gums.
• Fiber optic sensors are used in monitoring the physical health of structures such as buildings, bridges, dams, tunnels, monuments, pipelines and many others in real time.
Conclusions-
Optical sensors have proven in the past to be very simple and cost-effective devices. Because of the existence of many different optical principles which can be classified into use of direct optical detection or taking advantage of labeled compounds, in principle many of these methods can be applied to a huge number of applications. In some or the other form, optical fiber plays a very important role in today’s optical sensors. Looking at the industry trends in the past two decades, it seems that there is going to be a lot of improvements and researches to the existing optical sensors.
IC Temperature Sensors agreed that there is a major diversity of how thermal sensors read the heat, for example, a thermometer measures temperature with mercury rising as heat increases, showing the temperature on the side. However, thermometers only measure the temperature when it is close up to the heat source. Thermographic sensors are long ranged temperature measuring devices which makes them more ideal for this experiment. Thermographic sensors read the temperature using thermograms. Thermograms show a variety of different shades of color depending the temperature. The temperature is based off a number of different variables such as thermal radiation (2007). Thermal sensors that use thermography have many uses that they were created for. Thermal sensors are used in the military to detect explosives frequently. The marines use thermography to spot enemies also. Thermography is not only used by the military, it is also used for medical reasons such as detection of breast cancer (Flir Threat Detection,
In this two part lab we are to build a spectroscope from parts included with our lab kit to visualize and analyze the spectra of several light sources. In the second part of the lab we are to build a pinhole viewer. We are to then take the pinhole viewer and measure the diameter of the sun and moon. After completing both parts of the lab, there are several questions that need addressing. This paper examines and answers those questions.
A silicone semiconductor junction, in the shape of a diode was chosen to build the design around. This option filled all the requirements listed in the "Requirement Statement". Optional sensor devices were thermistors, thermometers, and thermocouples. These options were discarded because of high cost.
This transducer senses its surroundings by emitting and/or detecting infrared radiation (invisible electromagnetic radiation with longer wavelengths than those of visible light). They can also detect the person’s skin temperature through emitted black body radiation.
This light is referred to as plane polarized light (Weldegirma 2016). Polarimetry is also used to verify if a substance rotates the plane polarized light. The plane polarized light can rotate to the left, right, or not at all. A substance is considered optically active if it is able to rotate the plane polarized light to the either the left or right. A substance being optically active means that it has an enantiomer. To be optically active, the viewed substance must have a chiral center. A chiral center is defined as a carbon atom that has four different R groups linked to it. The positions of the 4 R groups determine which way the plane polarized light is rotated (Weldegrima 2016). Using a polarimeter to measure the substance’s optical rotation will help determine the optical purity of the substance. As polarized light passes through an optically active material, it rotates a certain amount. Measuring the degree of rotation of the polarized light will lead to the optical rotation being determined (Natt & Zhu, 2016). Polarimetric analysis of stereoisomers yields results that are represented in terms of Enantiomeric Excess (ee). Enantiomeric excess is also known as optical purity. To calculate the % ee the equation % ee = [α] Observed / [α] Pure * 100 is used. This equation allows
Philae is comprised of 3 Optical Spectrometers all together. It is used to measure light over a specific area of an electromagnetic field;
For both cases of IR thermography sensing methods and due to the wide variety of production conditions and material processes, there is a need to determine the relation between the detectors (IR camera) and material properties. The aim of this study is to find scalable relations that can be used in developing inspection systems using infrared thermography. The materials used are steel, aluminum and plastic representing three main materials used in common products. The scaling
An optical interferometer utilizes the phenomena of interference of light beams based on the wave nature of light. Two-beam interferometry is the most common tool for evaluating optical surfaces. The basic working principle of two beam interferometer is that two wavefronts of coherent light, one is called test object wavefront and other is called reference wavefront, recombine after travelling different paths and give an interference fringe pattern. The geometrical properties of the interference fringe pattern are determined by the difference in optical path traveled by the recombined wave fronts. The interferometers measure the difference in optical paths in units of wave length λ of the light used. Since the optical path is the product of the geometrical path and the refractive index of the medium, an interferometer measures either the difference in geometrical path when beams traverse the same medium or the difference of the refractive index when the geometrical paths are equal.
A halogen bulb light source was set up at the end of a yardstick, and a light sensor was set up on the yardstick beginning at 0.1m from the light source. Science Workshop was again used to measure the intensity of light ranging from 0.1m to 1.00m (Fig.
First, I would like to talk about infrared imaging. Infrared imaging is a technique of capturing invisible infrared images and converting them into visible images. Infrared imaging detects infrared radiation which is produce by all temperatures above absolute zero. Hot objects give out more infrared radiation than cooler objects. I have inspected a few of these in my couple of years as an inspector. I have mostly seen these units in airplane hangars, auditoriums,
Popp, W., Rasslan, O., Unahalekhaka, A., Brenner, P., Fischnaller, E., Fathy, M., . . . Gillespie, E. (2010). What is the use? An international look at reuse of single-use medical devices. International journal of hygiene and environmental health, 213(4), 302-307.
In this task, three methods of measuring temperature have been summarized. The fundamental physics and equations underlying the measurement, a figure supporting the description, a description of the range, accuracy and precision, advantages and disadvantages, and how these devices produce digital signals will be discussed in this task.
The interferometer is the most accurate device presently known to man, and most likely will remain the most accurate measuring device for the next hundred years” Cal Christiansen. The interferometer can measure lengths of one half the wavelength of the light source being used. With a HeNe laser (Helium Neon) this length is 316.4nm, about 1/3 of a micron. The interferometer is able to measure very small distances by the interference produced between two lasers beams. With this degree of accuracy there are clearly many uses for this device including, measuring flatness, structural stress, and making linear measurements.
With advances in micromachinery and easy to-use microcontroller stages, the jobs of sensors have reached out past the more standard fields of temperature, weight or stream estimation, for case into MARG sensors. Additionally, basic sensors, for instance, potentiometers and force recognizing resistors are still for the most part used. Applications fuse collecting and equipment, planes and flight, automobiles, remedy and mechanical innovation.
The amount of heat observes is sensed using sensor called temperature sensor. Mostly, there are two types of temperature sensor contact and noncontact. Examples of contact sensor are thermocouple, RTD, thermistor, thermometer, diodes, etc. And examples of noncontact sensors are radiation and pyrometers. The output of temperature sensor is smaller in amplitude as well as low signal power so amplifier is used to amplify weak signal.