A sensor is any machine, device, module, or system with an active or passive sensor application. Its purpose is to sense changes in its surroundings and send the data to some other electronic equipment, often a computer. A passive sensor is usually employed along with another electronic device. Examples of active and passive sensors are radar detectors, temperature detectors, and barometers. These devices are referred to as sensors because they detect signals or patterns from the environment, such as light, sound, heat and transmit data to an external observer, such as a receiver, who analyzes the data.
Non-Contact Temperature Sensor
Non-contact sensors refer to ones that can function without the need to touch the object being monitored physically. Rather than using a regular thermometer to measure a patient’s temperature, a nurse or physiciartican in clinics may employ an thermal imager. Such a thermometer is an example of non-contact temperature sensor technology that uses infrared radiation to establish a temperature reading – thus avoiding direct physical contact.
Non-contact temperature sensors generally rely on technologies based on electromagnetic or optical principles rather than on physical contact or mechanical movement to obtain temperature readings. The sensors often release radiation used to detect a condition without physical contact. The object which is being sensed or detected is generally referred to as the target object.
Non-Contact Sensor Technologies
In industries where sensors are used, there is a continuous trend of moving towards the adoption of non-contact sensors technology. Different fields, including medication, vehicle, modern, and flight, are a couple of the business sectors that express an appeal for these sensors. The essential reason for picking non-contact sensors is to limit the expense and increase the resistance of a device to wear and tear. Following are a couple of the common sensor technologies utilized in non-contact sensors. The innovation utilized in a particular sensor will especially rely upon the boundary or condition being monitored.
Hall Effect Sensor Technology
Hall effect sensor technology is used in many types of electronic and magnetic fields that use various electrical and magnetic properties to make measurements. It is used to control and maintain many different systems and machines. Many industries use Hall sensor technology, ranging from motors, engines, pumps to marine, aircraft, and communications systems. These types of measuring devices are used in everything from heating and cooling systems to medical devices and even military applications.
Hall effect temperature sensors are used in many applications in today’s world but not limited to thermal, optical, acoustic, and magnetic measurement. Hall effect sensors are used for applications where measurements need to be made constantly and continuously, either with or without humans monitoring the measurements.
Ultrasonic Sensor Technology
Ultrasonic sensors have recently found application in several industries where the basic principle of sonar is not applicable. By Using an ultrasonic sensor, the data is compressed into an appropriate signal that the computer can then process quickly and efficiently. Ultrasonic sensors use a diaphragm for receiving and emitting sound waves. A spring modifies the diaphragm when a change is detected in the object, changing the amount of voltage supplied to the sensor. The modified diaphragm produces a signal that is then measured by the circuit in the sensor. A commonly used type of ultrasonic sensor is a depth detector, where a light is used to indicate the depth of any object.
Inductive Sensor Technology
Inductive Sensor Technology is very well known for near-term proximity sensing of passive-conductive materials. Inductive sensors utilize currents induced by magnetic fields to detect metal objects. The inductive sensor uses an inductor to generate a high-frequency magnetic field. If an object is near the changing magnetic field, the current will flow in the target object. This resulting current flow sets up an all-new magnetic field that opposes the primary magnetic field. The net effect is that it changes the inductance of the coil in the inductive sensor.
Capacitive Sensor Technology
The working principle behind capacitive measurements relies on the principle of temperature conversion. If a liquid substance’s temperature is increasing, it will tend to evaporate into thin layers. These thin layers will gather together with the speed of thermal expansion. However, when the temperature reaches absolute zero, all the vaporized substances will return to their solid-state. A capacitor, then, is designed to have a high sensitivity that matches the changing temperature of the liquid substance being measured. It gives the user a measuring device that can function even when the environment changes, from room to room or from workstation to workstation.
Temperature measurement falls into two categories: contact and non-contact sensor. The non-contact sensor detects the amount of infrared radiation that the targeted object emits and responds quickly. They can be employed to measure temperatures of objects in movement or in a vacuum or to challenge access for other reasons.