Sensing Technology is one that detects and responds to inputs from the physical surrounding, be it light, pressure, heat, moisture, motion, smoke, or gas. Sensing systems processes the input in the control unit by means of embedded microprocessors and wireless communication systems, which in turn communicates to the output devices.
We have many kinds of sensors in use today, ranging from – position sensors, piezo sensors, thermos sensors, fluid property sensors, pressure sensors, force sensors, humidity sensors, sound sensors, frequency sensors, vibration sensors, strain sensors, photo sensors, and flow and level sensors. Many of the sensors use transducers or transmitters to convert the signals from sensing input to desired and calibrated electrical output. A temperature transducer converts thermal quantities to electrical quantities in digital displays for monitoring purposes, while further inputs are transmitted to controllers which use logic gates or consoles, or other forms of controllers to manage the sensing system.
ENGINEERING PROCESS MONITORING SYSTEMS: Process plants for chemical manufacturing, oil and gas pipelines, and transportation monitoring systems. A good example is GOOGLE MAP Navigation, which detects moving vehicles by remote sensing technology for real-time detection of vehicles, analysis of vehicle motion, and generation of traffic reports to guide transportation. Oil pipeline vandalization and leakage use piezoelectric sensors to measure pressure changes in oil and gas pipelines when there is leakage or vandalism resulting in pressure loss. Engineering facilities in buildings are monitored by means of sensing technology. Heating equipment like heat exchanger systems and boilers are monitored with thermoelectric sensors or thermocouples mostly in form of digital thermometers. Flow rates are monitored with flow meters in fluid flow systems, while pressure sensors read and record flow rates of fluids such as pumping stations, and mains feed. The fluid level in vessels and storage tanks is monitored with the aid of level monitors which are transduced to electronic displays. Liquid fuel, water and gas storage, and process flow systems benefit so much from sensing solutions.
ENVIRONMENTAL MONITORING SYSTEMS: An example of sensing technology in environmental monitoring system is lighting and acoustic control systems, which senses lighting levels and ambient noise levels, Photosensors detects luminous intensity (candela) or illuminance (lux or lumens/sqm), while noise level monitors senses sound levels (decibel, or hertz). Light sensors and remotely controlled lighting systems are good solutions for sensing technology.
Thermo-sensors read thermal impulses like ambient temperature. It applies RFID technology to detect temperature values (OC, OF, or K). Humidity sensors (hygrometers) detect, measure, and report the moisture content of mixed or pure gas as relative humidity (%) or specific humidity (g/kg), or absolute humidity (g/m3).
There are many gas sensors ranging from single gas detectors to multi-gas detectors, which reads the concentration of gases in the air or environment to know if there is gas leakage or loss, and risks of hazards from poisonous gases and combustible gases.
Wind speed (km/h, mph, ft/s, or knots) is read and reported by anemometer wind sensors, while wind pressure (pounds/ft2) are detected and reported by wind pressure sensors. Pollutants in air or water can be measured in (parts per million) using air quality sensors and water quality sensors like free chlorine and total organic carbon (TOC) sensors.
Environmental monitoring sensors are useful in heating, ventilation, air-conditioning and refrigeration systems, lighting systems, monitoring environments of agricultural systems in greenhouses, fisheries, poultry farms, hydroponics, weather monitoring systems, contaminants monitoring, and pollution control systems.
Environmental scientists monitor desertification, climate change, water bodies, urbanization, and population growth by the use of special analytics and imagery solutions that are based on sensing technology. Climatologists use remote sensing techniques to capture data for weather reports. Aerial surveying having motion sensing capability detects and records imagery for visualization of storms like cyclones, hurricanes, typhoons, and tsunamis.
Sensing is used in exploration geophysics and mineralogy for determining the stratification and layering of underground geological formations and mineral deposits by means of impulses from remote sounding to REMOTE SENSING EQUIPMENT. Seismologists use seismographs (SEISMIC SENSORS) to detect, analyze and quantify the magnitude of earthquake-triggering vibrations and convert them to wave patterns or digital displays. Volcanologists use also detect tremors due to volcanic disturbances. This is how sensing technology is used in earthquake and volcano surveys and mapping projects.
Surveyors, geologists, and geographers apply remote sensing techniques used for the production of geological maps by transmitting wave signals to help determine depths or altitudes by processing travel time. SONAR techniques are used in mapping the depth of seas, oceans, and other water bodies in hydrography. Sensing is applied in surveying equipment like Global Positioning Systems (GPS), total stations, digital theodolites, digital leveling instruments; Electromagnetic Distance Measurement (EDM) devices, and distance measuring devices based on LASER SENSORS.
Sensing technology is used in astronomy, space science, and cosmology to survey, map and monitor space objects, planetary systems, and star clusters by use of signal sensors incorporated with artificial intelligence and radar systems for monitoring of motions of objects in space. Astro-Surveyors make extensive use of sensing technology as in the Sloan Digital Sky Survey (SDSS), the Global Navigation Satellite System (GNSS), and telescopes equipped with space surveying systems.
Photography and videography make extensive use of motion sensors as in cine cameras for wildlife photography, sports motion pictures, and cinematography. Night vision cameras, camcorders, and security cameras are other photographic products of sensing technology.
Ionizing radiation sensors or nuclear radiation sensors are used to monitor the leakage of nuclear particles in nuclear laboratories, nuclear plants, or nuclear reactors by nuclear engineers, nuclear scientists, and physicists.
LIFE AND FIRE MONITORING SYSTEMS: Sensors that detect impulses that are associated with fire are of various types. Heat detectors sense heat by melting a fusible material, changing the heat load on bi-metallic metals, and detecting the rate of ambient temperature rise. They come as Rate-of-Rise Sensors or Fixed Temperature Sensors for the purpose of detecting the heating effect of fires in places where smoke sensors are not ideal. Smoke detectors mostly use smoke flow and thermal properties in detecting fire. Flame detectors detect radiation sent by flames by converting the radiant intensity of flames such as ultraviolet (UV) or infrared (IR) to voltage signals via a photoelectric means. Carbon monoxide (CO) sensors detect CO gas which is a product of combustion or fires and helps to prevent CO poisoning. Smoke detectors Aspirating smoke detectors are adopted where there is a need for highly sensitive fire detection systems or a need for very early detection of smoke by a sampling of air in the surrounding for smoke, vapors, or fumes. Beam sensors work based on absorption or scattering of light from the beam due to smoke presence. Some fire alarm sensors are multi-sensors having CO, heat, smoke, and flame detection, while others are combined by having any of the two detection forms in one device. Sensors for life and fire safety systems are useful in fire alarm and detection systems, gas leak detection systems, and fire suppression systems.
SECURITY MONITORING SYSTEMS: Sensors manually or automatically activates security systems. Scanners are used in airports for luggage and passengers use image sensing and processing for security checks. Some use metal detection sensors by transmitting magnetic fields to the environment or target and converting impulses to digital displays or alarms. Some security scanners transmit radiation like x-rays imagery to analyze various objects and display signals detecting in displays or digital outputs. Sensing technology using infrared imagery is useful in detecting the temperature of individuals having COVID-19 symptoms to help quarantine affected persons. Motion detectors are useful. Radio-frequency Identification (RFID) magnetic door sensors are used in access control security doors to control access. Fingerprint sensors, eye retina access control sensors, voice recognition door access, facial recognition access control, and card readers are among the most powerful access control solutions in the market today. Facial recognition scanning is useful in internet security for spotting identity theft and copyright infringements. Facial recognition scanning is used in tracking criminals and crime intelligence by forensic analysts and investigations in criminal justice and law enforcement organizations. The wireless joy sticks for camera controls like zoom, pan, tilt and rotate in surveillance camera systems, including the remote for controlling display screens or monitors work based on sensing technology. Some security gates and boom barriers (boom lifts) use remotely controlled with remote sensors for opening and closing in access control systems.
ENGINEERING QUALITY CONTROL: Many nondestructive material testing solutions use sensing technology to measure the engineering properties of materials. Structural fatigue of civil engineering and mechanical works are evaluated by the use of stress sensors. The thermal properties of engineering materials are also measured with the use of sensors in materials testing. Some of such tests applied testing of materials include – radiographic tests, through-transmission-tests, magnetic particle tests, ultrasonic tests, phased array tests, thermal infrared tests, microwave testing, acoustic emission tests, electromagnetic tests, and ground penetration radar. Pundit hammer – ultrasonic pulse velocity tests useful in civil engineering.
BIOMEDICAL MONITORING SYSTEMS: Systems that use scanners in diagnosing diseases like tumors, organ checks, and pregnancy checks, and orthopedics, like x-rays, ultrasound scans, computerized tomography (CT) scans, MRI scans, electrocardiograms, echocardiogram (ECG), positron emission tomography (PET) scan actually applies sensing technology in form of image processing. ECG is useful in psychoanalysis for the detection of brain waves displayed as wave patterns to monitor the level of disorderliness (entropy) in the brain. Heartbeat, heart pulse rate, and blood pressure are among health monitoring devices that are monitored based on transduction. Quantum Resonance Magnetic Analyzer (QRMA) uses a handheld sensor that reads radiations that are naturally transmitted by the body and produce results in health status reports of individuals being checked. Such reports may include – cardiovascular and cerebrovascular, bone growth index, rheumatoid bone disease, blood sugar, bone disease, bone mineral density, vitamin, gastrointestinal function, large intestine function, liver function, pancreatic function, kidney function, lung function, and brain nerve.
AUTOMATED ENGINEERING MACHINE SYSTEMS: Many electronic products use sensors, whether in aerospace, marine, automotive, communication, and automated manufacturing. Robotic machines, telecommunication satellites, and receivers like – world radio receivers, cell phones, television decoders, internet modems, and routers; and automation and control are among those that use sensing technology. Communication systems have extensive sensors and remote controllers that drive data capturing, data analytics, and communication channels of engineering systems by means of signal sensing and transmission.
Sensing technology assures the need for remote operation and flexibility when it comes to monitoring and control of systems.
William Nwaogu, Technical Advisor,
SAFETY CONSULTANTS & SOLUTION PROVIDERS LIMITED.
