Rigel Temperature Sensor
Rigel Temperature Sensor
Rigel has designed this temperature sensor to allow you to easily focus without worrying about temperature variations.
Telescopes change focus as temperature changes expand/contract the length of the telescope tube as temperature increases/decreases. Unlike internal temperature sensors located inside the controller that are affected by the heat generated by the electronics, the external temperature sensor can be attached to the telescope to get a more accurate measurement of the ambient temperature.