Drum thermometer with a Bourdon spring and scale illumination

摘要

The glow lamp for scale illumination of the thermometer is seated together with its bias resistor in a lamp holder which is designed as a push-in unit with side sliding contacts and is seated in the baseplate of the thermometer housing. The sliding contacts form the electrical connection for the power supply of the glow lamp. If the glow lamp is defective, the push-in unit can be replaced simply by pulling it out without any soldering work being required or cable connections having to be broken.