How the Breathalyzer Measures Alcohol in Your Breath
A 1954 invention by Robert Borkenstein that uses a chemical reaction to estimate the amount of alcohol in a person's blood by testing their breath.
Original patent title: “Apparatus for analyzing a gas”
A 1954 invention by Robert Borkenstein that uses a chemical reaction to estimate the amount of alcohol in a person's blood by testing their breath. Granted to Individual in 1958 with 8 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The device captures a specific volume of a person's breath and passes it through a chemical solution containing potassium dichromate and sulfuric acid. If alcohol is present in the breath, it reacts with the solution, causing a color change from orange to green. The device then uses a photoelectric cell to measure the intensity of this color change, which correlates to the concentration of alcohol in the breath and, by extension, the bloodstream.
The gap
What does this patent NOT cover?
- Does not cover modern digital fuel cell or infrared spectroscopy breath testing technology.
- Does not cover methods for testing alcohol concentration directly from blood or urine samples.
- Does not cover automated data logging or wireless transmission of test results.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
It cleverly used a simple color-changing chemical reaction as a proxy for blood alcohol content, allowing for a portable device that could be operated by police officers in the field rather than requiring a laboratory.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Original Breathalyzer 900 series
Early police sobriety checkpoints
Why it matters
The bigger picture
This invention transformed law enforcement by providing a portable, objective, and scientifically verifiable method for detecting drunk driving. It moved the legal standard for intoxication from subjective field sobriety tests to quantifiable chemical evidence.
Filed
May 10, 1954
Granted
February 25, 1958
Market context
Who's building on this
Companies in this space
While the original chemical-based Breathalyzer is largely obsolete, companies like Draeger and Intoximeters have built upon the foundational principle of breath-based alcohol detection using more advanced fuel cell and infrared sensors.
Market impact
This patent enabled the creation of the modern DUI enforcement industry. It established the legal and technical framework for breath testing, which remains a cornerstone of traffic safety and law enforcement globally.
Claim 1 — Plain English
What this patent covers
The device captures a specific volume of a person's breath and passes it through a chemical solution containing potassium dichromate and sulfuric acid. If alcohol is present in the breath, it reacts with the solution, causing a color change from orange to green. The device then uses a photoelectric cell to measure the intensity of this color change, which correlates to the concentration of alcohol in the breath and, by extension, the bloodstream.
The clever bit
It cleverly used a simple color-changing chemical reaction as a proxy for blood alcohol content, allowing for a portable device that could be operated by police officers in the field rather than requiring a laboratory.
What it does not cover
- Does not cover modern digital fuel cell or infrared spectroscopy breath testing technology.
- Does not cover methods for testing alcohol concentration directly from blood or urine samples.
- Does not cover automated data logging or wireless transmission of test results.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Limited data
Citation count
19/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$9K – $29K
Midpoint $18K · expired or expiring · industry ×1.6
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Borkenstein, R. F. (1958). How the Breathalyzer Measures Alcohol in Your Breath (U.S. Patent No. 2,824,789). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2824789/breathalyzer-borkenstein
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US2824789"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4405829 · 1983
How RSA Public-Key Encryption Keeps Digital Messages Secret
This patent describes the foundational RSA algorithm, a method for securely sending messages where anyone can encrypt a message using a public key, but only the intended recipient can decrypt it using a secret private key.
Massachusetts Institute of Technology
US 4575330 · 1986
How 3D Printers Build Objects Layer by Layer from Liquid
This patent describes the foundational method for 3D printing, where a machine builds a three-dimensional object layer by layer by hardening a liquid material with light or other energy.
UVP Inc
Semantically similar
You might also find these interesting
US 2058761 · 1936 · Arnold O. Beckman
How Arnold Beckman Invented the Modern pH Meter
US 2485586 · 1949 · International Standard Electric Corp
How the Geiger Counter Detects Invisible Radiation
US 3552770 · 1971 · Eaton Yale and Towne Inc
How Early Vehicle Airbag Safety Systems Work
US 2331117 · 1943 · CLAUDE R WICKARD
How the First Aerosol Spray Can Works
More to explore
More in Consumer Electronics
US 7657849 · 2010 · Apple Inc
How the iPhone's Slide-to-Unlock Gesture Works
US 7479949 · 2009 · Apple Inc
How Touchscreens Understand Your Finger Swipes and Scrolls
US 4528643 · 1985 · FPDC Inc
How Stores Make Custom Products On-Demand with Remote Approval
US 7469381 · 2008 · Apple Inc
How Touchscreens Show and Snap Back When You Scroll Past an Edge
New to patents?
Common Questions
Frequently Asked Questions
What does How the Breathalyzer Measures Alcohol in Your Breath cover?
A 1954 invention by Robert Borkenstein that uses a chemical reaction to estimate the amount of alcohol in a person's blood by testing their breath.
Who owns patent US 2824789?
Individual owns this patent, granted in 1958.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 2824789 cited by?
This patent has been cited by 8 later patents that build on its ideas.
What problem does this patent solve?
This invention transformed law enforcement by providing a portable, objective, and scientifically verifiable method for detecting drunk driving. It moved the legal standard for intoxication from subjective field sobriety tests to quantifiable chemical evidence.
What does this patent NOT cover?
Does not cover modern digital fuel cell or infrared spectroscopy breath testing technology.
Same assignee
More from Individual
Patent monitoring