Thermal Sensors Essay

ABSTRACT

A sensor is a device which coverts physical signal to the electrical signal.

Thermal sensors are temperature sensing devices which are small in size and made up of thermistors.

Thermal sensors are of many types:

Heat flux sensors, Infrared thermometer, Thermometer, Pyrometer,Flow sensors, Vacuum sensors , semiconductor sensors etc.

They found in laptops in order to sound an alarm when a certain temperature has been exceeded. They are used in electrical appliances and medical appliances, mobile communication equipment. The sensors having temperature-dependent properties which can be measured electrically include resistors, semiconductors such as diodes or thermocouples

In thermal sensors, radiations emitted by ground objects are

The technique of using the heat given off by an object to produce an image called thermal sensing.

They are widely used in night vision technologies and in environment without any light.

 General Working

Hotter objects emit radiations, according to the ambient temperature .This criteria is generally used in thermal imaging. It is a sensor which detects even a tiny variation in the temperature and collects the radiations and then convert or image it as an electronic one.

 Birth of thermal imaging

i. In the previous times, thermal imaging was introduced for military purposes for night visions and smoky areas. ii. In the late 1960s, Texas Instruments, Hughes Aircraft, and Honeywell developed single element detectors that scanned scenes and produced line images. These detectors led to the development of modern thermal imaging. iii. The pyro electric vidicon tube was developed by Philips and EEV first used by the Royal Navy for shipboard firefighting. iv. In 1978, Raytheon R&D group, patented ferroelectric infrared detectors, using barium strontium material that coats the thermal imager’s sensor.

 SENSORS USED

i. MICROCANTILEVER SENSORS are used in thermal