Understanding Thermal Imaging Device Specifications
Thermal Sensor Size – 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 three different sized sensors with its own designation: XM models use a 320×240 thermal sensor, XQ models use a 384×288 thermal sensor, and XP and XG models use a 640×480 thermal sensor.
Thermal Sensor Pixel Pitch – 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.
NETD – 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.
Refresh Rate – A high refresh rate (such as 50Hz) is best when choosing a thermal imager. A high refresh rate will result in a smooth image when panning or tracking fast-moving objects.