Depending on the type of detector

The detectors are contained in a vacuum-sealed container (Dewar) and cooled many degrees below zero Celsius by expensive cryogenic equipment. This greatly increases its sensitivity with respect to the ambient detectors, due to its large temperature difference with respect to the detected emitting body. If the detector were not cryogenically cooled, the ambient temperature of the detector would interfere with the temperature readings received by the detector.

The advantages of cryogenic detectors are:.

The disadvantages of cryogenic detectors are:.

Due to its high cost, its use is limited to the armed and security forces.

These operate at ambient temperature. The most modern ones use sensors that work by changing the electrical properties of the material of the emitting body. These changes (of current, voltage or resistance) are measured and compared to the operating temperature values ​​of the sensor. The sensors can be stabilized at an operating temperature above zero Celsius to reduce image perception interference, and therefore does not require cooling equipment.

The advantages of these detectors are:

But its disadvantages:

Since constant advances are being made in this field, the performance of these cameras is approaching those of cameras with cryogenic detectors.

Depending on the origin of the radiation

They emit infrared radiation with a reflector integrated into the camera or located elsewhere. The infrared beam illuminates the detected body, and the illumination is emitted by the body to be perceived by the camera and interpreted in a monochrome image.

The reflector has a filter to prevent the camera from being interfered with by observing visible light. If the reflector has a longer range, the larger the size and weight of its filter and the larger the battery size, because its power consumption increases. That's why most portable active cameras have a reflector with a range of 100 meters, but some manufacturers exaggerate the range of the cameras to several hundred meters.

They are also called thermal imaging cameras. They lack reflectors, and perceive infrared radiation as it is emitted by a body. They are the most common.

These cameras are used to track people in areas where it is difficult to see them (at night, smoke or fog), find recent traces of someone who has left a place, follow a particular car, see traces of moisture on certain surfaces, inspect industrial elements, etc.

Infrared sensor specifications include:

They were originally developed for military use in the Korean War. Cameras gradually migrated to other fields such as medicine or archaeology. More recently, optical advances and the use of sophisticated software interfaces have improved the versatility of this type of camera, for example, the body temperature can be known instantly, the camera can check if the temperature is higher than normal, and an audible alarm is triggered to identify the person.

Applications include:

The thermal camera, as a technological tool that helps in the workplace, has had a slow introduction in Spain and Latin America; On the other hand, in the United States its penetration into the world of work has been notably faster. Although its implementation in increasingly diverse areas has been progressively increasing, its use continues to be reduced in the field of scientific research, in civil protection forces, in fire departments and in the military field, that is, in the armed forces.

As far as the use of thermal cameras in the field of research is concerned, in Spain the Universitat Politècnica de Catalunya stands out, which used this type of camera in the research of the NanoSatLab project.[1]​ Also in Spain, the use of thermal cameras stands out in the field of fire departments, with examples such as the installation of a fire detection system with a thermal camera in the municipality of Vacarisses,[2]​[3]​ or the incorporation of cameras thermal in drones and helicopters of the fire departments of the Valencian Community and the Community of Madrid respectively.[4]​[5]​[6]​.

Regarding the use of the thermal camera in Latin America and the United States, it is covering more and more different work areas. Regarding the use of the thermal camera in scientific research in Latin America, the recent use that has been given to this type of cameras in the field of veterinary medicine in Mexico stands out, where a thermal camera was used to check the state of health of a sea lion at the Aragon Zoo.[7] Thermal cameras have also been used in Mexico by civil protection forces, more specifically by search and rescue teams in order to locate victims among the rubble of the earthquake that hit the country. in 2017.[8]​ In the military field, thermal cameras have been incorporated as useful combat tools in armored cars and drones by the armies of Chile and the Eastern Republic of Uruguay respectively.[9]​[10]​ There are also ways to use thermal cameras for non-professional or work purposes, as in the curious case that occurred in Colombia, in which criminals used this type of device to detect the heat traces left by ATM users in the keys where they entered their secret numerical combination.[11]​ Finally, the use of thermal cameras by security forces, such as the police, is quite widespread in the United States, and they have even managed to find victims of rape thanks to this type of technology.[12]​.

Depending on the type of detector

The detectors are contained in a vacuum-sealed container (Dewar) and cooled many degrees below zero Celsius by expensive cryogenic equipment. This greatly increases its sensitivity with respect to the ambient detectors, due to its large temperature difference with respect to the detected emitting body. If the detector were not cryogenically cooled, the ambient temperature of the detector would interfere with the temperature readings received by the detector.

The advantages of cryogenic detectors are:.

The disadvantages of cryogenic detectors are:.

Due to its high cost, its use is limited to the armed and security forces.

These operate at ambient temperature. The most modern ones use sensors that work by changing the electrical properties of the material of the emitting body. These changes (of current, voltage or resistance) are measured and compared to the operating temperature values ​​of the sensor. The sensors can be stabilized at an operating temperature above zero Celsius to reduce image perception interference, and therefore does not require cooling equipment.

The advantages of these detectors are:

But its disadvantages:

Since constant advances are being made in this field, the performance of these cameras is approaching those of cameras with cryogenic detectors.

Depending on the origin of the radiation

They emit infrared radiation with a reflector integrated into the camera or located elsewhere. The infrared beam illuminates the detected body, and the illumination is emitted by the body to be perceived by the camera and interpreted in a monochrome image.

The reflector has a filter to prevent the camera from being interfered with by observing visible light. If the reflector has a longer range, the larger the size and weight of its filter and the larger the battery size, because its power consumption increases. That's why most portable active cameras have a reflector with a range of 100 meters, but some manufacturers exaggerate the range of the cameras to several hundred meters.

They are also called thermal imaging cameras. They lack reflectors, and perceive infrared radiation as it is emitted by a body. They are the most common.

These cameras are used to track people in areas where it is difficult to see them (at night, smoke or fog), find recent traces of someone who has left a place, follow a particular car, see traces of moisture on certain surfaces, inspect industrial elements, etc.

Infrared sensor specifications include:

They were originally developed for military use in the Korean War. Cameras gradually migrated to other fields such as medicine or archaeology. More recently, optical advances and the use of sophisticated software interfaces have improved the versatility of this type of camera, for example, the body temperature can be known instantly, the camera can check if the temperature is higher than normal, and an audible alarm is triggered to identify the person.

Applications include:

The thermal camera, as a technological tool that helps in the workplace, has had a slow introduction in Spain and Latin America; On the other hand, in the United States its penetration into the world of work has been notably faster. Although its implementation in increasingly diverse areas has been progressively increasing, its use continues to be reduced in the field of scientific research, in civil protection forces, in fire departments and in the military field, that is, in the armed forces.

As far as the use of thermal cameras in the field of research is concerned, in Spain the Universitat Politècnica de Catalunya stands out, which used this type of camera in the research of the NanoSatLab project.[1]​ Also in Spain, the use of thermal cameras stands out in the field of fire departments, with examples such as the installation of a fire detection system with a thermal camera in the municipality of Vacarisses,[2]​[3]​ or the incorporation of cameras thermal in drones and helicopters of the fire departments of the Valencian Community and the Community of Madrid respectively.[4]​[5]​[6]​.

Regarding the use of the thermal camera in Latin America and the United States, it is covering more and more different work areas. Regarding the use of the thermal camera in scientific research in Latin America, the recent use that has been given to this type of cameras in the field of veterinary medicine in Mexico stands out, where a thermal camera was used to check the state of health of a sea lion at the Aragon Zoo.[7] Thermal cameras have also been used in Mexico by civil protection forces, more specifically by search and rescue teams in order to locate victims among the rubble of the earthquake that hit the country. in 2017.[8]​ In the military field, thermal cameras have been incorporated as useful combat tools in armored cars and drones by the armies of Chile and the Eastern Republic of Uruguay respectively.[9]​[10]​ There are also ways to use thermal cameras for non-professional or work purposes, as in the curious case that occurred in Colombia, in which criminals used this type of device to detect the heat traces left by ATM users in the keys where they entered their secret numerical combination.[11]​ Finally, the use of thermal cameras by security forces, such as the police, is quite widespread in the United States, and they have even managed to find victims of rape thanks to this type of technology.[12]​.