An Optix Pyro meter in its case - lid missing. German. Used for measuring temperature of hot stuff from a distance. Aim and focus at your hot object (metal or fire or lava). Inside, there's a small electric filament bulb, similar to a light bulb. The device uses lenses to focus the hot object's radiation onto the filament, which is also glowing from an electric current. You turn a dial (rheostat) to increase or decrease the current to the filament. You adjust until the filament's brightness and colour perfectly blend with the background (the object's image) – it looks like it disappears. At this point, the filament and the object are the same colour/brightness, meaning they are at the same temperature. The current flowing through the filament is directly related to its temperature, which is then displayed as the object's temperature. Now you know.
1960's - 2000's.
W7.5 x D7.5 x H24 cm.
Untested.
