WHY THERMAL IMAGING?

Thermal imaging is an invaluable technology which works to highlight objects that would usually remain invisible in total darkness, daylight, and even in dense fog when thermal contrast is low.

Using infrared radiation and thermal energy, thermal imaging devices gather information about objects through a thermal sensor (microbolometer) attached to a special type of lens (usually made from Germanium) to formulate clear images of the observed objects.

In general, thermal images are grayscale – with white representing heat, black representing colder regions (or vice versa), and various shades of grey indicating gradients of temperatures between the two. However — for improved identification and varying applications — newer thermal imaging cameras can now add colour to the images they produce, using colours such as orange, blue, yellow, red, and purple.

Similar to digital cameras, thermal sensors are measured in pixels; generally speaking, the bigger the sensor the better the picture, as a larger sensor can capture more detail. Pulsar thermal imagers use one of four differently sized sensors, each with its own designation. XM models use a 320x240 thermal sensor, XQ models use a 384x288 thermal sensor, XP and XG models use a 640x480 thermal sensor, and XL models use a 1024x768 thermal sensor.

This is the distance between the centre of the pixels. A smaller pixel pitch results in finer image quality and a physically smaller thermal sensor. However, a larger pixel offers more sensitivity. A sensor with a smaller pixel pitch will have a greater base magnification than a thermal imager with the same size lens and a greater pixel pitch. Pulsar XM & XG sensors have a 12µm pixel pitch, and XQ and XP sensors have a 17µm pixel pitch.

Noise Equivalent Temperature Difference (NETD) is a measurement of the smallest temperature difference a thermal device can detect. The lower the value, the more sensitive the device becomes — performing better than a device with a greater NETD value in conditions that are challenging to thermal imagers such as cold, fog, and rain. A device’s NETD rating is an important indicator as to how well it will perform.