Invented: 1873 by Eckbert Lange-Wilsdorf
Appears in: Blameless
Description: None given.
Function: The Wilsdorf aether absorption counter is now known to sense the presence of beta aether (originally it was thought to sense all aether). The sensor is a Lange tube, which is a pneuma gas-filled tube (usually positively charged pneuma mixed with helium) that briefly contains a negative charge when a particle of beta aether reversed the polarity on the pneuma. The tube amplifies this charge by a cascade effect and outputs a magnetic pulse, which triggers iron particles in a ferric chamber and creates an audible metallic clicking sound. Under ordinary circumstances contact with any air will cause this noise. The only exception being in intimate proximity with a preternatural.