US5400637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method of checking calibration of breath alcohol measuring instrument with barometric pressure compensation
Assignee: Intoximeters Inc
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Filing: 1993-12-21
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Granted: 1995-03-28
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Expires: 2013-12-21
Abstract
Abstract A system and method for checking the calibration of a breath alcohol measuring instrument by the use of alcohol standards all containing substantially identical concentrations of alcohol and the use of a calculator which generates an expected measured value for the standard based on the known alcohol concentration and current atmospheric pressure.
Inventors
- 👤 Glenn C. Forrester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:30
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0006; G01N33/48; G01N33/483; G01N33/497; G01N33/4972; Y; Y10; Y10S; Y10S436/00; Y10S436/90; Y10T; Y10T436/00; Y10T436/10; Y10T436/100833
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
In combination, a breath alcohol measuring instrument, a plurality of dry pressurized gas standards for checking calibration of the instrument, each of the standards containing a preselected concentration of alcohol, the concentration in each of the standards being identical within a tolerance allowed the instrument, and a calculating means for calculating an expected value to be produced by the measuring instrument when a predetermined amount of the standard is measured by the instrument, the calculating device means comprising a pressure transducer means for producing a signal dependent on atmospheric pressure and an arithmetic unit means for producing the expected value from the signal and a predetermined factor based on the preselected concentration of alcohol.
Claim 2
Dependent Claim
114 words
In combination, a breath alcohol measuring instrument, a plurality of dry pressurized gas standards for checking calibration of the instrument, each of the standards containing a preselected concentration of alcohol, the concentration in each of the standards being identical within a tolerance allowed the instrument, and a calculating means for calculating an expected value to be produced by the measuring instrument when a predetermined amount of the standard is measured by the instrument, the calculating device means comprising a pressure transducer means for producing a signal dependent on atmospheric pressure and an arithmetic unit means for producing the expected value from the signal and a predetermined factor based on the preselected concentration of alcohol.
Claim 3
Dependent Claim
24 words
The combination of claim 1 wherein the concentration of alcohol in each of the standards varies by less than plus or minus five percent.
Claim 4
Independent Claim
142 words
A method of checking calibration of a breath alcohol measuring instrument, the instrument producing an output representative of blood alcohol, the output being substantially independent of atmospheric pressure, the method comprising a step of providing a plurality of containers containing dry pressurized gas standards, each of the standards containing a preselected concentration of alcohol, the concentration of alcohol in each being identical within the tolerance allowed the instrument, a step of using one of the standards with the instrument to produce an output, and a step of calculating an expected value to be produced by the measuring instrument when a predetermined amount of the standard is measured by the instrument, the calculating step comprising producing a pressure signal dependent on atmospheric pressure and deriving an expected value from the pressure signal and a predetermined factor based on the preselected concentration of alcohol.
Claim 5
Independent Claim
142 words
A method of checking calibration of a breath alcohol measuring instrument, the instrument producing an output representative of blood alcohol, the output being substantially independent of atmospheric pressure, the method comprising a step of providing a plurality of containers containing dry pressurized gas standards, each of the standards containing a preselected concentration of alcohol, the concentration of alcohol in each being identical within the tolerance allowed the instrument, a step of using one of the standards with the instrument to produce an output, and a step of calculating an expected value to be produced by the measuring instrument when a predetermined amount of the standard is measured by the instrument, the calculating step comprising producing a pressure signal dependent on atmospheric pressure and deriving an expected value from the pressure signal and a predetermined factor based on the preselected concentration of alcohol.
Claim 6
Dependent Claim
24 words
The method of claim 3 wherein the concentration of alcohol in each of the standards varies by less than plus or minus five percent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-27 | 1998-09-26 | 1999-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-27 | 2002-09-26 | 2003-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-27 | 2006-09-26 | 2007-03-28 | $7700.00 | Window Closed / Lapsed |