Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Ionization detector

Patent ·
OSTI ID:6506127
An ionization detecting fire alarm device is disclosed which comprises a double chamber structure, a source disposed in at least one of the chambers, and a vernier adjusting screw electrode protruding into one chamber. The chamber containing the adjustable electrode is more open to the atmosphere than the other chamber. Porting is provided between chambers and detection occurs by sensing the rate of change of ionization current in the chamber structure. The source or sources, one being in each chamber, is a beta source such as a nickel 63 source. A change in ionization current is detected by a unique circuit of this invention which comprises a programmable unijunction transistor oscillator circuit.
Assignee:
Gamewell Corp.
Patent Number(s):
US 4121105
OSTI ID:
6506127
Country of Publication:
United States
Language:
English