You can freely build on How the Geiger Counter Detects Invisible Radiation
This patent expired in 1967. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
International Standard Electric Corp
Patent granted
1949
Expired
1967
Forward citations
6
What this patent covers
The device functions by using a sealed tube filled with a specific gas at low pressure. When a radioactive particle enters the tube, it ionizes the gas, creating a brief electrical pulse between the electrodes. This pulse is then amplified and recorded as a 'click' or a numerical count, providing a direct measurement of radiation levels in the immediate environment.
What is now free to use
All 0 claims of US 2485586 are in the public domain. Specifically:
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover solid-state radiation detectors like silicon diodes
Does not cover scintillation counters that use light-emitting crystals
Does not cover the fundamental physics of ionization itself
Does not cover digital signal processing or modern computer-based data analysis
Who is building on this today
Modern manufacturers like Thermo Fisher Scientific and various specialized nuclear instrumentation companies continue to refine the sensitivity and portability of gas-filled radiation detectors.
Products built on expired version of this technology
Handheld radiation survey meters
Laboratory contamination monitors
Geiger-Muller tubes in nuclear research
How to cite this patent in your documentation
International Standard Electric Corp . US Patent 2485586. Geiger counter. Granted 1949, expired 1967. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.