Learn About Thermal Imaging Cameras for Surveillance Applications

From process safety to maritime threat detection, thermal imaging cameras are used in a wide range of oil, gas, and marine applications. Nonetheless, they often retain an "aura of mystery" that leaves many unsure of when and where they should be used to provide the most operational value.

Below, we answer some frequently asked questions to help resolve the issue.

No, these terms are often used interchangeably, which can lead to confusion as to where thermal technology is best used.

Infrared cameras detect light reflected from objects (near-infrared light), which means that in complete darkness a light source is required - usually an integrated infrared LED. Thermal cameras, however, operate by detecting differences in radiation emitted by objects.

This means that thermal cameras require a completely different design - most notably using materials such as germanium instead of glass as optics to suit the operating wavelength. The sensors used also need to be different in order to respond appropriately to photon detection.

Yes, thermal imagers can detect objects at farther distances than infrared. This is because they work by measuring emissivity rather than capturing reflected light,

Active illumination of cameras equipped with IR LED illumination has only a limited working range, typically around 200m, and is largely dependent on the reflectivity of the target. As distance increases and the camera's field of view narrows or zooms in, light attenuation increases requiring more powerful illuminators, so it becomes a law of diminishing returns.

Thermal imager, on the other hand, operates passively in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) bands and their operating range is limited only by the camera lens and sensitivity.

For thermal imagers, DRI (Detection, Recognition, and Recognition) is based on the Johnson standard, where resolution is defined by the smallest line pair (lp) or pixel value, where a line pair is defined as a white line adjacent to a black line in the captured thermal on the image. While the minimum lp value for Detect is 1, Recognition is 3 and Recognition requires 6.

Using this criterion, "detection" confirms the existence of an object, "recognition" enables the type of object or class to be identified, such as a person or a car, and "recognition" enables a specific object or class to be identified, such as the type of car.

A few good examples are flare stack analysis or monitoring liquid levels in tanks in the oil and gas sector. In both cases, the ability to operate in low/no light conditions is still essential and the target itself may be invisible for detection, i.e. heat level, and gas composition (different gases will have different emissivities), but shorter detection ranges and higher precision imaging are not a priority. Thermal imaging cameras offer the ideal solution and a more cost-effective option.

While thermal imaging cameras do offer many advantages, many of them are lost when looking at monitoring for retrospective use only (i.e. for recording and review).

For example, thermal imaging cameras will not provide the same detailed evidence review capabilities as electro-optical cameras. Their strength lies in active monitoring – as an early warning mechanism for approaching objects, mechanical failures, and process problems. In conclusion, thermal imaging cameras are the ideal first line of defense when it comes to critical detection capabilities in low/no light conditions.

In the long run, they can. It is important to mention LED degradation. In just five years, LED light sources typically degrade by about 30%, which can significantly impact camera capabilities and image quality. Thermal cameras will require a larger initial outlay, but they will last much longer.

The above briefly describes some differences between thermal imagers and infrared cameras. If you want to buy or customize thermal imagers and infrared cameras, please contact us.

JAVOL is a professional custom infrared imaging equipment manufacturer. Relying on the multi-spectral high-sensitivity photoelectric sensor chip of advanced compound semiconductor materials, with deep learning AI algorithm as the engine, it integrates low-light night vision technology, infrared thermal imaging technology, short-wave infrared technology and other spectrums Technology fusion technology, our company designs, develops and manufactures advanced imaging products and system solutions, which are widely used in machine vision, autonomous driving, drone payloads, high-end manufacturing, medical diagnosis, and other fields.