Designing a 21 × 21 mm thermal core into your housing: mounting, connector, power and the window
Once the sample works on the bench, the next questions are mechanical: how big is it with the lens, how do you mount it, what does it need for power, and what goes in front of it. Here is a checklist with figures from MINI 640-2 Radiometric. Most points apply to any small uncooled core.
Size and weight
- Core: 21 × 21 × 10.3 mm, under 8.6 g without the lens
- 9.1 mm lens: 10.5 g
- Total length with the 9.1 mm lens: about 25.3 mm (±0.5 mm) on the reference drawing
Longer lenses add length and weight, so get the drawing for your lens before you fix the housing. A 2D drawing is available on request.
Mounting
The body has M2 threaded holes on its sides, 3 mm deep on the reference drawing. Mount it by the body, not by the lens, and keep the bracket stiff. The manual lists 6.06 g random vibration on all axes and 80 g / 4 ms shock, but a loose bracket will still blur the image on a moving platform.
Connector and power
The core uses a 50-pin Hirose DF40 board-to-board connector (DF40C-50DP-0.4V, 0.4 mm pitch) and runs from a single 5 V supply. Typical power is under 0.7 W with USB output at 25°C. For evaluation, use the USB Type-C board supplied with the sample. For your own carrier board, tell us which hardware documents you need and we will check with the manufacturer, and check the logic levels of the interfaces you use.
The window: glass does not work
Ordinary glass and most plastics are opaque between 8 and 14 μm, the band these cores see. If the core needs a window, use an infrared material such as germanium with an anti-reflection coating for that band.
On a radiometric product the window also absorbs and reflects part of the signal, so readings drop. Either correct for the window’s transmission in your software, or check readings against a reference with the window fitted. Keep the window close to the lens so it does not clip the edges of a wide field of view.
Heat
The core’s own temperature affects its readings. Keep it away from processors, regulators and motors, give it a stable path for heat, and keep warm parts of the housing out of its view and away from the window, where they can reflect into the image.
Environment
Imaging is specified from −40°C to +80°C, but temperature measurement only from −10°C to +70°C ambient. If your product works outdoors in winter, plan a heater or an insulated enclosure for measurement work. Humidity is listed as 5–95% non-condensing, so condensation on the window needs a design answer too.
Request the drawing for your configuration.
Tell us the lens and the interface you plan to use. We reply within 24 hours on working days.