# Energy sensors2 second review

6. Sep 2012
1 von 44

### Energy sensors2 second review

• 1. Course Code: 2EC307 Review - 2 Energy Sensors VRUSHABH SANGHAVI (09BEC115) DEEP ADHVARYU (09BEC104) UNDER THE GUIDANCE OF PROF. N. P. GAJJAR
• 2. What is Energy? In Physics, energy is an indirectly observed quantity. When matter is changed into energy (such as energy of motion, or into radiation), the mass of the system does not change through the transformation process. Energy is the capacity of a system to do work. The total energy contained in an object cannot be created nor be destroyed in accordance with the law of conservation of energy.
• 3. What are Sensors? A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.  For accuracy, most sensors are calibrated against known standards. Left: Thermocouple used as Temperature Sensor
• 4. A good sensor obeys the following rules: Should be sensitive to the measured property Should be insensitive to any other property likely to be encountered in its application Does not influence the measured property Ideal sensors should be designed to be linear or linear to some simple mathematical function of the measurement.
• 5. Sensor Characteristics Sensitivity Range Stability Repeatability Linearity Error Response Time
• 6. Factors taken into consideration while designing Environmental Factors Economic Factors Temperature Range Cost Humidity Availability Corrosion Size Lifetime Over range protection Susceptibility to EM interferences Ruggedness Power Consumption Self test Capability
• 7. Energy Sensors An Energy Sensor is a device, which responds to an input quantity by generating a functionally related output usually in the form of an electrical or optical signal. Above: Pictures Of Energy Sensors
• 8. Importance Of Energy Sensors Sensors are pervasive. They are embedded in our bodies, automobiles, airplanes, mobile phones, chemical plants, industrial plants and countless other applications. Sensors are used in everyday objects such as touch-sensitive elevator buttons (tactile sensor) and lamps which dim or brighten by touching the base. There are also innumerable applications for sensors of which most people are never aware. Applications include cars, machines, aerospace, medicine, manufacturing and robotics.
• 9. Sensors are needed to convert physical data available in the form of different kinds of energies for analytical and control purposes into electrical signals.
• 10. Application Of Sensors Sensors are used in:  Fire Alarms(in picture)  Smoke Detector  OTEC (Ocean Thermal Energy Conversion)  Wind Turbine Transmission Monitoring  Wind Turbine Lubrication Systems
• 11. • Hybrid Engine Testing • Materials and Component Testing • Hydraulic Systems Testing • Handling Systems for Nuclear Fuel Rods Systems Testing
• 12. Types Of Sensors
• 13. Classification Of Energy Sensors Sensors may be classified according to the various energies it can detect. They are:- 1. Mechanical Energy Sensors 2. Thermal Energy Sensors 3. Nuclear Energy Sensors 4. Solar Energy Sensors 5. Seismic Energy Sensors
• 14. Mechanical Energy Sensors  Mechanical Energy Sensors are the sensors that detect a change in the mechanical energy of the system.  Mechanical quantities: displacement, Strain, rotation velocity, acceleration, pressure, force/torque, twisting, weight, flow  Here we will consider sensors for displacement, velocity, acceleration, pressure.
• 15. Some of the mechanical energy sensors are:  Capacitive Accelerometer for Acceleration Sensing  Piezoelectric accelerometer for Acceleration Sensing  Metal foil strain-gauge based (load cell) for force sensing  LVDT (Linear Variable Differential Transformer)  Scanning Laser Vibratometry for velocity sensing (a) Capacitive Accelerometer (b) Linear Variable Differential Transformer
• 16. Capacitive accelerometer Acceleration SensingAccele Good performance over low frequency ration Sensing range, can measure gravity! Heavier (~ 100 g) and bigger size than piezoelectric accelerometer Measurement range up to +/- 200 g More expensive than piezoelectric accelerometer Sensitivity typically from 10 – 1000 mV/g Capacitive Frequency bandwidth typically from 0 Accelerometer to 800 Hz Operating temperature: -65 – 120 C
• 17. Piezoelectric accelerometer Acceleration Acceleration SensingAccele Sensing Nonzero lower cutoff frequency (0.1 – ration Sensing 1 Hz for 5%) Light, compact size (miniature accelerometer weighing 0.7 g is available) Measurement range up to +/- 500 g Less expensive than capacitive accelerometer Sensitivity typically from 5 – 100 Piezoelectric Accelerometer mv/g Broad frequency bandwidth (typically 0.2 – 5 kHz) Operating temperature: -70 – 150 C
• 18. Metal foil strain-gage based (load cell) Force Sensing Good in low frequency response High load rating Resolution lower than piezoelectricity-based Rugged, typically big size, heavy weight load cell
• 19. Piezoelectricity based (force sensor) Force Sensing lower cutoff frequency at 0.01 Hz • can NOT be used for static load measurement Good in high frequency High resolution Limited operating temperature Piezoelectric Based (can not be used for high Force Sensor temperature applications) Compact size, light
• 20. LVDT (Linear Variable Differential Transformer): Displacement Sensing  Inductance-based electromechanical sensor  “Infinite” resolution  limited by external electronics  Limited frequency bandwidth (250 Hz typical for DC-LVDT, 500 Hz for AC- LVDT)  No contact between the moving core and coil structure  no friction, no wear, very long operating lifetime  Accuracy limited mostly by linearity  0.1%-1% typical Linear Variable  Models with strokes from mm’s to 1 m Differential available Transformer
• 21. Scanning Laser Vibrometry Velocity Sensing  No physical contact with the test object; facilitate remote, mass-loading-free vibration measurements on targets  measuring velocity (translational or angular)  automated scanning measurements with fast scanning speed  However, very expensive (> \$120K) Scanning Laser Vibratometer
• 22. Thermal Energy Sensors The Sensor used to detect heat energy is known as Heat Energy Sensor or Thermal Sensors. The simplest example of a heat energy sensor is a thermocouple. It provides a voltage proportional to the temperature across its junctions.
• 23. Thermistors Thermal Sensors Thermistors have negative temperature coefficient Therm istor 1 3{ 2 They are non-metallic made of metallic Thermal Resistor oxides like manganese, nickel, cobalt or copper. The electrical resistance of material change with temperature They come in different forms: 1.Disc type 2.Washer type 3.Bead type 4.Rod type
• 24. Bimetallic Strip Temperature Sensor L = L 0[1 + β (T - T0)] Application Thermostat (makes or breaks electrical connection with deflection)
• 25. Heat Flux Sensor  A heat flux sensor should measure the local heat flux density in one direction. The result is expressed in watts per square meter. The calculation is done according to:  Where Vsen is the sensor output and Esen is the calibration constant, specific for the sensor.  Heat flux sensors generally have the shape of a flat plate and a sensitivity in the direction perpendicular to the sensor surface.
• 26. Heat Flux The total heat flux is composed of a Sensor conductive, convective and radiative part. Depending on the application, one might want to measure all three of these quantities or single one out. An example of measurement of conductive heat flux is a heat flux plate incorporated into a wall. Heat Flux Plate The gold sensor only measures convective heat flux, the black sensor measures radiative as well as convective heat flux. A small air temperature sensor is added to estimate local heat transfer coefficients Heat Flux Sensor
• 27.  a sensor sensitive to radiative as well as convective heat flux is a Gardon or Fire Sensing Schmidt–Boelter gauge, used for studies of fire and flames.  The Gardon must measure convection perpendicular to the face of the sensor to be accurate due to the circular-foil construction, while the wire-wound geometry of the Schmidt-Boelter gauge Gardon or Schmidt can measure both perpendicular and Boelter gauge showing parallel flows. the instrument main components
• 28. Nuclear Energy Sensors Nuclear potential energy is the potential energy of the particles inside an atomic nucleus. This category of inventions has tremendous amount of patents. There are a number of sensors or detectors which were invented lately to detect nuclear potential energy.
• 29. Images of Nuclear Energy Sensors from Patents filed: Apparatus for Sensing Radioactivity
• 30. HVAC Radioactivity Sensors  sensors are engineered to the highest standards in performance and reliability. HVAC claims that it will help improve facility’s environment while cutting utility expenses and equipment costs Temperature and Radioactive sensors by HVAC
• 31. Solar Energy Sensors The Solar Radiation Sensor, or solar pyranometer, measures solar radiation, the sum at the point of measurement of both the direct and diffuse components of solar irradiance. Left: Dual Solar Sensor from GE Electronics Sensing
• 32.  The sensor’s transducer, converts incident Pyranometer radiation to electrical current, is a silicon photodiode with wide spectral response.  The transducer is an hermetically-sealed silicon photodiode; the included amplifier converts the transducer current into 0 to +2.5 VDC Connections
• 33. Sensors from Hukseflux Solar Sensor Hukseflux manufactures and sells pyranometers (global solar radiation), pyrheliometers (direct solar radiation) and albedometers (solar radiation balance) The most common applications of these instruments are in measurement of the available solar energy (for use of solar radiation as a source of renewable energy), climatology (for assessing local climate and Hukseflux energy balance) and building physics. Pyrheliometer DR01
• 34. GE Sensors For Cars Dual solar Sensor The dual solar sensor uses two photo diode cells inside of it to measure the intensity of the light that enters into the cabin of the vehicle. It then takes this information and feeds it back to the Dual solar Sensor by GE automatic temperature control (ATC) unit of Electronics the vehicle's air conditioning system. The air temperatures of the driver's side and passenger side are then automatically adjusted up or down depending upon the amount of light entering both sides of the vehicle.
• 35. Light Sensors  A light sensor detects presence of light.  The best example of light sensor is photodiodes.  Thorlabs' C-Series Photodiode Power Meter Sensors cover a wide power and wavelength range. These sensors are offered in standard, slim, integrating sphere, and compact fiber versions to meet your specific application requirements.
• 36. • Light sensitive variable resistors. Photo resistors • Its resistance depends on the intensity of light incident upon it. – Under dark condition, resistance is quite high (MΩ: called dark resistance). – Under bright condition, resistance is lowered (few hundred Ω). • Response time: – When a photo resistor is exposed to light, it takes a few milliseconds, before it lowers its resistance. Photoresistors – When a photo resistor experiences removal of light, it may take a few seconds to return to its dark resistance.
• 37.  Photo resistors exhibit a nonlinear Photo Resistors characteristics for incident optical illumination versus the resulting resistance. log10 R = α − β log10 P Symbol 104 R 103 102 101 101 102 103 104 Relative illumination (P)
• 38. Seismic Energy Sensors  Seismic Sensors have shown their applicability to target bearing, range, and classification problems in the battlefield monitoring and perimeter defense system.  This kind of sensor can perform accurate measurements of small ground vibration and monitor seismic activity due to their high sensitivity to dynamic strains induced by acceleration variations.  Seismometers and Accelerometers are available for this purpose.
• 39. Seismic Sensors by HP and Shell Seismic Sensors Hewlett-Packard Co. and Shell announced that they are developing a new wireless sensing system for acquiring high-resolution seismic data. Improved and increasingly powerful computer technology has over the years Microelectromechan enabled the seismic images to become ical Systems increasingly precise, with the possibility of deploying thousands of sound detectors, often in a grid pattern that enables geophysicists to build a three-dimensional image of the subsurface
• 40. Fiber Bragg grating sensors for Seismic Sensors seismic wave detection seismic sensors based on the optical fiber Bragg grating. This kind of sensor can perform accurate measurements of the seismic activity due to their high sensitivity to dynamic strains caused by small ground vibrations. Light weight and compact 125 micro centimeter in diameter
• 41. Seismic wave detection system based Seismic on fiber optic sensor Sensors Optical fiber sensors using fiber Bragg grating have a number of advantages such as immune to electromagnetic interference, lightweight, and low power consumption. The basic principle of the FBG seismic sensing system is that it transforms the acceleration of ground motion into the strain signal of the FBG sensor through mechanical design, and after the optical demodulation generates the analog voltage output proportional to the strain changes.
• 42. Bibliography Materials Today Ophir Wikipedia Bosch Security Systems General Electronics(GE) Hukesflux Thorlabs Shell Corporation
• 43. HP Electronics Energy max – Coherent Inc Physics Tutorial Sunfish Alarm Systems Electronic Instrumentation by H S Kalsi
• 44. “Thank You”