GB2184245A - Breath alcohol measuring appliance - Google Patents
Breath alcohol measuring appliance Download PDFInfo
- Publication number
- GB2184245A GB2184245A GB08629760A GB8629760A GB2184245A GB 2184245 A GB2184245 A GB 2184245A GB 08629760 A GB08629760 A GB 08629760A GB 8629760 A GB8629760 A GB 8629760A GB 2184245 A GB2184245 A GB 2184245A
- Authority
- GB
- United Kingdom
- Prior art keywords
- alcohol
- arrangement
- passage
- measuring appliance
- ofthe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/483—Physical analysis of biological material
- G01N33/497—Physical analysis of biological material of gaseous biological material, e.g. breath
- G01N33/4972—Determining alcohol content
Abstract
In a breath alcohol measuring appliance which detects the alcohol concentration by means of an alcohol sensor (3) and is provided, preferably in a shunt passage (31) branching from the respiration passage (5), with a hot temperature-dependent resistor (33) acting as a flow sensor the output signal of which is integrated by components (57,59) for ascertaining that a minimum respiratory air volume has been exhaled, the integrator is controlled by a resetting circuit (71) and switch (75) responding to the direction of flow in the respiration passage, which circuit liberates the integrator for the integration when respiratory air is flowing in the exhalation direction and resets it, and keeps it reset for the duration of the inhalation action, when respiratory air is flowing in the inhalation direction. The resetting circuit (71) comprises a differentiating circuit (81) and an amplifier (83) which closes the switch (75) to discharge integrating capacitor (59) when resistor (33) is no longer cooled by exhaled air. The resistor is screened against inhaled air by a non-return valve (35). <IMAGE>
Description
SPECIFICATION
Breath alcohol measuring appliance
The invention relates to a breath alcohol measuring appliance having a measuring arrangementwhich detects the alcohol concentration ofthe respiratory air exhaled through a respiration passage by means of an alcohol sensor, having a flow sensor including at least one temperature-dependent resistor exposed to the respiratory aircurrent,which flow sensor deiivers at least one th roughput signal representing the respiratory airthroughputthrough the respiration passage, having an integrator arrangement which time-dependently integrates the throughput signal forthe ascertaining ofthe respiratoryairvolumebreathed out by way ofthe respiration passage and liberating the measuring arrangementforthe measurement ofthe alcohol concentration on orafterthe reaching of a pre-determined minimum breath volume, and having a control arrangement connected to the flow sensor and detecting the direction of flow ofthe respiratory air in the respiration passage,which blocks the measurement of the alcohol concentration if inhalation is effected before the liberation of the measurement by the integrator arrangement.
A breath alcohol measuring appliance of the above kind is known from German Patent No. 2,428,352. In this measuring appliance monitoring is effected as to whether within a pl e-determined time interval exhalation is effected at least with a minimum respiratory airthroughput, in ordertoensurethatthe measurement of the alcohol concentration is carried out on alveolarair. If during the minimum time period the minimum respiratory airthroughput is understepped, the measurement of the alcohol concentration does not take place, or its invalidity is indicated.Forthe measurement ofthe minimum throughput a temperature-dependent resistor is provided in the respiration passage, which is arranged in the feedback branch of a sum-and-difference amplifier and determines the amplification thereof in dependence upon the respiratory air cooling. The sum-and-difference amplifier delivers a signal representing the respiraiory airth roughputto a threshold value stage which in turn, in the case offalling short ofthe minimum throughputfixed forthe exhaling of alveolar air, generates a fault signal indicating the invalidityofthealcohol measurement.
To the sum-and-difference amplifierthere is further connected an integrator which in inhaling integrates the respiratory airthroughputforthe ascertaining ofthe entire inhaled respiratory air volume The value of the entire inhaled respiratory airvolume is stored and in exhaling is compared with the exhaled airvolume, likewise ascertained by the integrator. A comparator ascertains when the rninimum respiratoryairvolumewhich renders possible the alcohol measurement on alveolar air has been exhaled.
In the respiration passage ofthe known measuring appliance there is arranged a second temperature-dependent resistorwhich is screened off in the exhalation direction by a restrictor. Thus the second temperature-dependent resistor is cooled by different amounts in inhaling and exhaling. The resuitant different resistances are detected by means of a threshold value stage which generates a fault signal representing the direction of flow in inhaling. In orderto preclude faulty measurements by reason of breath manipulations the alcohol measurement is rejected as invalid if within the ascertaining ofthe minimum respiratory airvolume which ensures measurement on alveolar airthefaultsignal representing the inhaling direction was generated.
The known measuring appliance already delivers an invalid alcohol measurement if during the determination ofthe minimum respiratory air volume inhaling occurs, even if only briefly, or breathing is halted only briefly. Since the measurement ofthe alcohol concentration, including in police use, is to take place even with unwilling or nervously excited persons, operating errors can occurwhich lead to an invalid measurement.
From German Patent No. 2,522,932 a further breath alcohol measuring appliance is known in which the temperature-dependent resistor arranged in the respiration passageforthe ascertaining of the direction of flow of the respiratory air is connected between a voltage source and a differentiating member. The differentiation member responds to the speed of variation ofthe currentflowing through the temperature-dependent resistor, which in turn is a measure for the direction offlow of the respiratory air.
It is the problem of the invention to improve a measuring appliance ofthe initially explained kind so that valid alcohol concentration measurements can be carried out on alveolar air even in the case of respiration faults.
On the basis ofthe breath alcohol measuring appliance as initially explained, this problem is solved in accordance with the invention in that the control arrangement resets the integrator arrangement on detecting airflowing in the inhalation direction and blocks itforthe duration of the inhalation condition forthe integration ofthe throughput signal. Delaying or briefly ceasing exhalation thus does not lead to invalidity ofthe measurement, since the minimum breath volume is ascertained by time integration ofthe respiratory air throughput andthetime period until the reaching of the minimum breath volume is not limited. Even if inhaling is effected briefly, this does not necessarily lead to invalidity of the alcohol concentration measurement.The volume value ascertained by the integratorarrangement is setto zero and inthesame breath integration is begun anew in the subsequent inhalation. The alcohol concentration measurement takes place in every case only after uninterrupted exhaling ofthe predetermined minimum breath volume. The integratorarrangementand/orthe control arrangement for detecting the direction of flow, also further components of the measuring appliance, can also be realised by a microprocessor.
In the known breath alcohol measuring appliance several temperature-dependent resistors are arranged in the respiration passage containing the alcohol sensor in a preferred form ofembodimentof the invention it is provided that the flow sensor comprises one single temperature-dependent resistor which is arranged in a shunt passage branching offfrom the respiration passage and leading separately to atmosphere and that the shunt passage contains, on the side placed to atmosphere in the direction offlow, a screening device which screens the temperature-dependent resistor in the inhalation direction. In this way it is possible to reduce the current consumption ofthe measuring appliances, which are usuallytransportable and fed mains-independentlyfrom batteries.Not only is the number reduced ofthetemperature-dependent resistors, which are formed for example as hot conductors and heated in the rest condition to a temperature of at least 700 C., preferably about 100" C., but it is also possible to set the speed of flow in the shunt passageto suitable measurement values, independentlyoftheflowcross-section ofthe respiration passage.
The screening device can be a restrictor placed to atmosphere in the exhalation direction. Such a restrictor permits a flow cooling ofthe temperature-dependent resistor forthe measurement ofthe throughput, but prevents flow cooling in the inhalation direction and thus permits the detection of the direction offlow. In a preferred form of embodiment howeverthe screening device is a non-return valve blocking in the inhalation direction. The non-return valve mechanically blocks theflowofrespiratoryairin the inhalation direction through the shunt passage, whereby a relatively simple recognition of direction of flow is rendered possible, preferably by means of a differentiating arrangement.
The integrator arrangement can liberate the measuring arrangementforalcohol measurement directly on reaching of the minimum breath volume.
Since however the measurement accuracy of the measuring arrangement is the greater, the greater is the proportion of alveolar air in the respiratory air, in a preferred form of embodiment it is provided that a delay arrangement delays the liberation ofthe measuring arrangement beyond the reaching of the minimum respiratory air volume. The delay arrangement responds to the throughput signal or a signal derived from it and liberates the measuring arrangementforthe measurement of the alcohol concentration before the end of the breath is reached or before the next-succeeding inhaling action. Due to the delay of the liberation it is possible to increase the accuracy of the alcohol measurementwithout detriment to the security against manipulation.The delay arrangement expediently responds to the speed of variation of the integrated throughput signal and liberates the measuring arrangementfor the measurement of the alcohol concentration when thespeed of variation drops below a pre-determined threshold value which indicates the end ofthe breath. in orderto preclude faults the delay arrangement is liberated for its operation,through the integratorarrangement, onlywhen the minimum respiratoryairvolume is reached.
The alcohol sensor is expediently a fuel cell responding specifically to alcohol vapour in the air of the breath and delivering an output signal proportional to the alcohol concentration. Sincefuel cells inherently possess a certain response time and a certain recovery time, they are expediently not lastingly exposed to the current of respiratory air.In a preferred form of embodiment of the measuring appliance the measuring arrangement includes a piston suction pump the suction chamber of which is connected with the respiration passage through a connecting passage which branches offfrom the respiration passage and the piston of which, which limits the suction chamber, is movable manually againsttheforceofa return spring into its minimum suction chambervolume position and by the return spring into its maximum suction chambervolume position. The piston is arrestable in the minimum position by means of an electro-magnetically unlockable locking device which is controlled by the integration arrangement. The locking device is unlocked when the minimum breath volume is reached, wherebythe piston suction pump sucks a breath air sample from the respiration passage.The alcohol concentration measurement takes place by reference to this breath air sample. Although the above piston suction pump is preferred, other forms of em bodi ment are also usable within the scope of the invention. Byway of example the pump can be equipped with a drive magnet to stress the return spring,orthe piston can be movable two andfro between the minimum position and the maximum position by means of a drive device which can be set in action in two drive directions, for example a two-way magnet.
An example of embodiment ofthe invention isto be explained in greater detail below by reference to drawings, wherein :
Figure 1 shows a diagrammatic representation of the breath alcohol measuring appliance; Figure2shows a circuit diagram of a control circuit ofthe measuring appliance which determines the time momentofmeasurementand Figures3a -dshowtime diagrams of signals occurring in the circuit according to Figure 2.
In Figure 1 a control and measuring circuit of a breath alcohol measuring appliance is designated by 1 which, by means of an alcohol sensor 3, measures the alcohol concentration ofthe breathed air exhaled through a respiration passage 5 in the direction of thearrow7 and, calibrated in values ofbloodalcohol concentration, displays it in a measured value indicator device 9. The alcohol sensor 3 which expediently is a fuel cell responding specificallyto alcohol vapour, measures the alcohol concentration in a breath air sample sucked in buy a piston suction pump 11 through a connection passage 13 branching off from the respiration passage 5. The measurement moment when the piston suction pump 11 takes the breath airsample is fixed bythe control and measurement circuit 1.
The piston suction pump 11 has a housing 15 in which a piston 17 is displaceableagainsttheforceof a return spring 19 by means of a press knob 21 in the direction of the reduction of the volume of a suction chamber 23 limited by the housing 15 and the piston 17. By means of an electro-magnetically unlockable locking device, represented diagrammatically at 25, the piston 17 can be arrested in its position determining the minimum volume of the suction chamber 23 by means of a bolt 27 initially stressed resiliently into the locking position.The locking device 25 is unlocked by energisation of an electro-magnet 29 controlled by the control and measuring circuit 1 ,wherebythe return spring 19 moves the piston into the position determining the maximum volume of the suction chamber 23 and the breath airsample is sucked outofthe respiration passage5.
Furthermore a shunt passage 31 openingto atmosphere independently of the respiration passage 5 branches off from the respiration passage 5. In the shunt passage 31 there is arranged a temperature-dependent resistor 33 on the side of which facing to atmosphere in the exhalation direction there is arranged a non-return valve 35 opening in the exhalation direction and closing in the inhalation direction. The non-return valve 35 comprises a ball 37 which is pressed by a spring 39 with very slight spring force which merely ensures a closure position of the ball 37 independentofthe position of installation. The force ofthe spring 39 is preferably so small that the back pressure occurring in the exhalation direction in the shunt passage 31 is negligible.Thetemperature-dependent resistor 33 is cooled in dependence upon the respiratory air throughput in the shunt passage and thus in predetermined manner in dependence upon the respiratory airthroughput in the respiration passage 5. The resistance variation caused bythecooling is exploited by means ofthe control and measuring circuit 1 for the control of the time moment for the taking ofthebreathairsampleandforthe recognition of breath manipulations which can lead to measurementerrnrs.
Figure 2 shows a control circuitsuitableforthe control of the locking device 25 in combination with a temperature-dependent resistor 33 formed as hot conductor. The hot conductor 33 is connected in series with a resistor 41 in the form ofa voltage-divider circuit between working voltage terminals designated by + and -. A voltage divider circuit consisting of resistors 43 and 45 is further connected to the working voltage terminals + and, the voltage divider tapping 47 of which circuit is connected with the circuit earth 49 and keeps the circuit earth at a pre-determined potential.The currentflowing through the hot conductor 33 heats the hot conductor 33 to a temperature of at least 70
C., preferably about 100" C. The voltage related to a reference potential, for example earth, occurring at the voltage divider tapping 51 between the hot conductor 33 and the resitor 41, is a measure forthe respiratory airthroughput in the shunt passage 31 and hus a measure forthe respiratory air thrcughput ofthe respiration passage 5 in the exhalation direction 7. With growing respiration air throughput the hot conductor 33 is cooled to an increasing extent, whereby its resistance grows and the voltage on the voltage dividertapping 51 increases.
Acontrollable integrator 53 is connected tothe voltage divider tapping 51 through a direct-current break capacitor 55 and a series coupling resistor 57.
The integrator 53 comprises an integration capacitor 59 connected by way of the capacitor 55 and the series resistor 57 between the voltage divider tapping 51 and earth,totheterminal of which remote from earth the inverting input of a sum-and-differenceamplifier6l,working as threshold value switch, is connected. The non-inverting input ofthe sum-and-difference amplifier 61 is connected with a reference voltage souce 67, here positive, formed by resistors 63,65.
The integrator 53 integrates the voltage on the voltage divider tapping 51, representing the respiratory airthroughput of the respiration passage 5, and delivers a signal corresponding to the exhaled breath airvolume at the terminal ofthe integration capacitor 59 remote from earth. The reference voltage of the reference voltage source 67 is set so that the signal energising the electromagnet 29 of the locking device 25 is generated on the output 69 of the sum-and-difference amplifier61 when a minimum volume of respiratory air has been breathed out,which ensures that the respiratory air availableforthe respiratoryairsamplecomesfrom the alveoles ofthe lungs.
The integrator 53 is controlled by a resetting circuit 71 responding to the direction offlow of the respiratory air and comprises a controllable switch 75 which is connected in parallel with the capacitor 59 and is opened and closed in alternation bythe resetting circuit 71. During the integration action the switch 75 connected in parallel with the integration capacitor 59 is opened. In resetting the switch 75 is closed.
The resetting circuit 71 includes a differentiating member, designated by 81 and consisting of a series capacitor77 and a parallel resistor 79 connected for one partto earth andfortheotherpartthroughthe series capacitor 77 with the voltage dividertappings 51,to which member a sum-and-difference amplifier 83 working asthresholdvalueswitch is connected with its inverting input. The sum-and-difference amplifier 83 is connected with its non-inverting input to a voltage divider circuitformed from resistors 87, 89 and serving as reference voltage source 85, and controls the switch 75. The differentiating member 81 and the reference voltage source 85 are so dimensioned that the resetting circuit71 liberates the integrator 53 for the integration of the voltage on the voltage divider tapping 51, representing the throughput, when respiratory air is flowing in the exhalation direction and thus cooling the hot conductor 33, and resets it and keeps it resetforthe duration of inhalation when respiratoryairisflowing in the inhalation direction in the respiration passage 5. Fortheduration of inhalation the non-return valve 35 is closed, so that the hot conductor 33 heats up in stationary ambient air with pre-determined temperature variation rate.The rate of variation is detected by means of the differentiating member 81 and the series-connected sum-and-difference amplifier 83, working asthreshold value switch.
Details ofthe manner ofworking appearfrom
Figures 3a - 3d, which sheathe course ofthe voltage at different points of the circuit according to Figure 2, in dependence upon the timet. Figure 3a shows the voltage U1, representing the respiratory air throughput, onthe voltage dividertapping 51 for an exhalation beginning atthe time moment to, where inhalation takes place briefly between the time momentst1 andt2. and ending atthe momentt3.
When subjected to breath in the exhalation direction the hot conductor 33 is cooled and the voltage U1 rises. Between to and t2 inhaling takes place, whereby the hot conductor 33 heats up with pre-determined variation rate in the shunt passage 31 blocked by the non-return valve 35, while the voltage U1 drops. In the following exhalatioh between tl and tithe voltage U1 rises again as a result ofthe cooling ofthe hot conductor 33. After the end ofthe breath application atthe momenttthe hotconductor33 can heat up again, whereby the voltage U1 decreases.
Figure 3b shows the voltage U2 at the output ofthe sum-and-difference amplifier 83. In the case of a high level of the voltage U2 the integrator 53 is set back and in the case of a low level of the voltage U2 it is liberated forthe integration ofthe voltage U1.
Figure3cshowsthe outputvoltage U3ofthe integrator 53 at the terminal ofthe integration capacitor 59 remote from earth. In Figure 3cthe threshold voltage level Us pre-determined bythe reference voltage source 67 and determining the minimum breath air volume is entered in dot-and-dash lines. In the period to to tl the integral does not reach the value ofthe threshold voltage Us before it is set back to zero at the momentt1. The integration action begins afresh at the momentt2 on renewed exhalation and at the momentt4 reaches the threshold voltage Us. The integral voltage U3 rises further and is set back atthe momentt3 atthe end ofthe breath application. Figure3d shows the voltage U4atthe output69 ofthesum-and-difference amplifier 61, that is the control voltage for the locking device 25.A circuit connected to the output 69 here utilises onlythe here rising frontflank of the voltage pulse.
Figure 2 shows in chain lines a variant of the control circuit in which the measuring arrangement is liberated forthe measurement ofthe alcohol concentration with delay after the reaching ofthe minimum respiratory airvolume. Due to the delay of the measurementmomentthe alveolar air proportion in the respiratory air sample and thus the accuracy of measurement of the alcohol meter are increased. The delay arrangement comprises a differentiating member 91 connected with the integrator output, which delivers a signal corresponding to the speed of variation ofthe integral ofthe throughput signal to a threshold value stage 93.The locking device 25 is connected to the output 95 of the threshold value stage 93 instead of to the output 69, and is unlocked through this stage when the speed of variation drops below a predetermined threshold value denoting the end of the breath. In order to prevent the unlocking before the predetermined minimum respiratory airvolume is reached, the threshold value stage 93 has a release input 97, to which the sum-and-difference amplifier 61 is connected and by way of which it is liberated for the monitoring ofthe speed of variation only after the minimum respiratoryairvolume is reached.
The differentiating member 91 can be omitted if the threshold value stage 93 is coupled directly to the voltage dividertapping 51 and monitors the dropping of the throughput signal at the end ofthe breath. This variant is distinguished by relatively low circuitry expense. The monitoring of the speed of variation of the integral of the throughput signal has however the advantage that momentaryfluctuations of the throughput signal cannot lead prematurely to the unlocking ofthe locking device 25.
Claims (10)
1. Breath alcohol measuring appliance, having a measuring arrangement (1) detecting the alcohol concentration ofthe respiratory air exhaled through a respiration passage (5) by means of an alcohol sensor (3), having a flow sensor (33,41) comprising at leastonetemperature-dependent resistor (33) exposed to the flow of respiratory air and delivering at least one throughput signal representing te respiratory airthroughput through the respiration passsage, having an integrator arrangement (53,61) time-dependently integrating the throughput signal for ascertaining the respiratory airvolume exhaled through the respiration passage and liberating the measuring arrangement (1) for the measurement of the alcohol concentration on or after the reaching of a pre-determined minimum breath volume, and having a control arrangement (71) connected to the flow sensor (33,41) and detecting the direction of flow of the respiratory air in the respiration passage, which control arrangement blocks the measurement of the alcohol concentration if inhalation occurs before the liberation of the measurement by the integrator arrangement (53,61), characterised in that the control arrangement (71) resets the integrator arrangement (53,61) on detection of airflowing in the inhalation direction and blocks itforthe integration of the throughput signal forthe duration of the inhalation condition.
2. Alcohol-measuring appliance according to
Claim 1 ,characterised in thatthe flow sensor comprises one single temperature-dependent resistor (33) which is arranged in a shunt passage (31) branching offfrom the respiration passage (5) and leading separatelyto atmosphere, and in that theshunt passage (31) contains, onthe side placedto atmosphere in the exhalation direction, a screening device (35) which screens offthe temperature-dependent resistor (33) in the inhalation direction.
3. Alcohol-measuring appliance according to
Claim 2, characterised in that the screening device is formed as non-return valve (35) blocking in the inhalation direction.
4. Alcohol-measuring appliance according to
Claim 2 or3, characterised in thatthe temperature-dependent resistor is formed as a hot conductor (33) connected to a current source and is kept by current heating at a temperature higher than the temperature ofthe respired air and in that the control arrangementfordetecting the direction of flowcomprisesa differentiating arrangement (81 ).
5. Alcohol-measuring appliance according to
Claim 4, characterised in thatthe hot conductor (33) in the state of rest is heated to a temperature of at least 705 C.
6. Alcohol-measuring appliance according to one of Claims 1 to 5, characterised in that a delay arrangement (91,93) delays the liberation ofthe measuring arrangementforthe measurementofthe alcohol concentration after reaching ofthe pre determined minimum breath volume.
7. Alcohol-measuring appliance according to
Claim 6, characterised in that the delay arrangement (91,93) includes a threshold value device (93) controllable in dependence upon the throughput signal, which liberates the measuring arrangement for the measurement of the alcohol concentration when the respiratory airthroughputfalls short of a pre-determined threshold value, and inthatthe integrator arrangement (53, 61 ) blocks the threshold value device (93) before the pre-determined
minimum breath volume is reached and liberates it
after this volume is reached.
8. Alcohol-measuring appliance according to Claim 7, characterised in that the threshold value device (93) includes a differentiating arrangement
(91) and responds to the integral ascertained by the
integrator arrangement (53,61).
9. Alcohol-measuring appliance according to
one of Claims 1 to 8, characterised in thatthe
measuring arrangement comprises a piston suction
pump (11 )the suction chamber (23) of which is
connected with the respiration passage (5) byway of
a connection passage (13) branching off from the
respiration passage (6) and the piston (17) ofwhich,
limiting the suction chamber (23), is manually movable againsttheforce of a return spring (19) into
its minimum suction chamber volume position and
bythe return spring (19) into its maximum suction
chambervolume position, in that the piston (17) is
arrestable in the minimum position by means of an
electro-magnetically unlockable locking device (25),
in that the alcohol sensor (3) detects the alcohol
concentration in the suction chamber (23) and in that the integration arrangement (53,61) controls the
locking device (25).
10. Breath alcohol measuring appliance as
claimed in Claim 1 substantially as described with
reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19853543973 DE3543973A1 (en) | 1985-12-12 | 1985-12-12 | BREATH ALCOHOL MEASURING DEVICE |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8629760D0 GB8629760D0 (en) | 1987-01-21 |
| GB2184245A true GB2184245A (en) | 1987-06-17 |
| GB2184245B GB2184245B (en) | 1989-10-11 |
Family
ID=6288295
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8629760A Expired GB2184245B (en) | 1985-12-12 | 1986-12-12 | Breath alcohol measuring appliance |
Country Status (3)
| Country | Link |
|---|---|
| DE (1) | DE3543973A1 (en) |
| FR (1) | FR2591750A1 (en) |
| GB (1) | GB2184245B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4902628A (en) * | 1988-08-24 | 1990-02-20 | Guardian Technologies, Inc. | Apparatus and method to deter circumvention of a breath sobriety test |
| US4914038A (en) * | 1988-06-17 | 1990-04-03 | Guardian Technologies, Inc. | Apparatus and method for avoiding circumvention of an identity confirming breath tester |
| EP0384217A1 (en) * | 1989-02-18 | 1990-08-29 | Drägerwerk Aktiengesellschaft | Device for supplying a sample into the measuring chamber of a sensor and measuring method therefor |
| US5321972A (en) * | 1992-01-15 | 1994-06-21 | Dragerwerk Aktiengesellschaft | Method for quantitatively determining a component of a gas flow and apparatus therefor |
| WO2004104576A1 (en) * | 2003-05-23 | 2004-12-02 | Sensatronic Gmbh | Device for conveying a fluid volume, device and method for the analysis thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3842515A1 (en) * | 1988-12-16 | 1990-06-21 | Lmb Laborservice Gmbh | Sampling device for an apparatus for detecting a component in gas, in particular alcohol in exhaled air |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1374142A (en) * | 1971-06-18 | 1974-11-13 | Borg Warner | Breath testing system with breath temperature variance compensation |
| US4132109A (en) * | 1977-07-22 | 1979-01-02 | Alcohol Countermeasure Systems, Inc. | Breath testing system |
| US4163383A (en) * | 1978-03-07 | 1979-08-07 | Alcohol Countermeasure Systems Inc. | Breath testing system |
| CA1143179A (en) * | 1978-11-03 | 1983-03-22 | Thomas P. Jones | Gas sampling devices |
| DE2906908C2 (en) * | 1979-02-22 | 1983-02-24 | Drägerwerk AG, 2400 Lübeck | Procedure and arrangement for taking samples when determining the breath alcohol content |
| DE2906864A1 (en) * | 1979-02-22 | 1980-09-04 | Draegerwerk Ag | METHOD FOR DETERMINING THE ALCOHOL CONTENT IN BREATHING AIR |
| AU516365B2 (en) * | 1979-04-23 | 1981-05-28 | James George Blackwell | Breath on recirculating ignition system |
| GB8405481D0 (en) * | 1984-03-02 | 1984-04-04 | Lion Lab Ltd | Gas analysis |
| FR2577677B1 (en) * | 1985-02-15 | 1988-04-29 | Legrand Guy | DEVICE FOR ANALYZING THE ALCOHOL CONTENT OF A GAS |
-
1985
- 1985-12-12 DE DE19853543973 patent/DE3543973A1/en not_active Withdrawn
-
1986
- 1986-12-12 FR FR8618000A patent/FR2591750A1/en not_active Withdrawn
- 1986-12-12 GB GB8629760A patent/GB2184245B/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU614163B2 (en) * | 1988-02-18 | 1991-08-22 | Dragerwerk Aktiengesellschaft | Device for conveying a sample to be measured into the measuring chamber of a measuring sensor and measuring process relating thereto |
| US4914038A (en) * | 1988-06-17 | 1990-04-03 | Guardian Technologies, Inc. | Apparatus and method for avoiding circumvention of an identity confirming breath tester |
| US4902628A (en) * | 1988-08-24 | 1990-02-20 | Guardian Technologies, Inc. | Apparatus and method to deter circumvention of a breath sobriety test |
| EP0384217A1 (en) * | 1989-02-18 | 1990-08-29 | Drägerwerk Aktiengesellschaft | Device for supplying a sample into the measuring chamber of a sensor and measuring method therefor |
| US5321972A (en) * | 1992-01-15 | 1994-06-21 | Dragerwerk Aktiengesellschaft | Method for quantitatively determining a component of a gas flow and apparatus therefor |
| WO2004104576A1 (en) * | 2003-05-23 | 2004-12-02 | Sensatronic Gmbh | Device for conveying a fluid volume, device and method for the analysis thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3543973A1 (en) | 1987-06-19 |
| GB2184245B (en) | 1989-10-11 |
| GB8629760D0 (en) | 1987-01-21 |
| FR2591750A1 (en) | 1987-06-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |