The Draeger 6820 includes 3 Mouthpieces, additional Mouthpieces are available in packs of 100 (product code 6266) or 1000 (product code 6269). Full European Approval for Police use
Regular Recalibration required every 6 months UK based 12 month warranty. A free copy of FTA Drink and Drugs Driver Card (code 4121) is included with every order
Thanks to its wide range of possible configurations, the handheld instrument can be easily adapted to meet different international regulations and guidelines. Because the Draeger Alcotest 6820 offers intuitive operation, it is easy to use and precise measurement results can be obtained within a very short period of time.
Automatic sampling and calibration processes make the instrument easy to use. All measurement functions are controlled via a single key, while menu navigation is by two menu keys. The special way the mouthpieces are designed means they can be fitted quickly and securely even in poor light conditions.
Wireless Printer
A portable printer system is available for the 6820 allowing instant wireless printing of results. It comes as standard with a 220/110v supply but can also operate as a mobile printer chargeable from either a 12v car or USB supply.
Integrated data logger
The last 5000 results with their respective test numbers, date and time are stored in the data logger. Individual results can either be called up from the log by pressing the menu keys or transferred to a PC with the optional AlcoView Software and Interface Cable.
- Short response times even at high alcohol concentrations
- Automatic or manual activated sampling, each with quantitative display of a value
- Print results to optional mobile printer via wireless interface
- Internal Memory for 5000 test results
- Data transfer to PC (Optional)
- Easy and intuitive handling - no specialist training required
- Low blowing resistance
- Tests possible with very low breath volume
- Patented NRV (non return valve) mouthpieces available
- Attachment of mouthpiece is easy, safe and fast
- Test results via illuminated display, LED and beeper signals
- With Alkali-batteries over 1,000 measurements are possible at room temperature
Will this Breathalyser stand up in a court of law?
The 6820 is Home Office approved so the information can be used in a court of law provided the unit has a current recalibration certificate.
The Draeger 6820 is Home Office approved so can be used as evidence in a court of law provided it has a current recalibration certificate. How does a Breathalyzer Work?
When you drink, alcohol is digested in the stomach and passes through the stomach wall into the blood stream. Broadly speaking, neat alcohol (such as a straight whisky for example) drunk on an empty stomach is likely to enter the bloodstream more quickly than, say, a milk-based cocktail drunk after a fairly full meal. This does not mean you will become more intoxicated from the straight whisky - just that the effect is likely to be felt more quickly. Once in the blood stream it passes around the body and generates the usual effects of alcohol on the body and brain. As the blood passes through the liver it is gradually filtered from the bloodstream, reducing at each "pass" until there is no longer any residual alcohol in the body. It also passes through the alveoli in the lungs, and as you breathe and the oxygen passes into the bloodstream, so does some of the alcohol in your blood "evaporate" into the air in your lungs. It is this alcohol that a Breathalyser is designed to measure. This is why it is necessary to measure deep lung air when using a Breathalyzer, and why it is important not to drink within 15 minutes of testing - otherwise alcohol that remains in your mouth will be blown directly into the detector, at far higher concentrations than is the case from alcohol that has passed through the stomach, into the bloodstream, and into the air you breathe out. Clearly the concentrations are often very low and the sensors have to be very sensitive to detect the levels involved - hence why it is so important not to smoke or drink before using them and why obtaining an accurate and consistent sample of air is so important.
The Chemistry of a Fuel Cell Breathalyzer
For those with a technical interest, when the user exhales into the breathalyzer, any ethanol present in their breath is oxidized to acetic acid at the anode: CH3CH2OH(g) + H2O(l) → CH3CO2H(l) + 4H+(aq) + 4e- At the cathode, atmospheric oxygen is reduced: O2(g) + 4H+(aq) + 4e- → 2H2O(l). The overall reaction is the oxidation of ethanol to acetic acid and water: CH3CH2OH(l) + O2(g) → CH3COOH(l) + H2O(l). The electrical current produced by this reaction is measured, processed, and displayed as an approximation of overall blood alcohol content by the breathalyzer.
Homeostatic variables and Partition Ratios
Breathalyzers assume that the subject being tested has a 2100-to-1 partition ratio in converting alcohol measured in the breath to estimates of alcohol in the blood. This measure is in direct proportion to the amount of grams of alcohol to every 1 ml of blood. However, this assumed partition ratio varies from 1300:1 to 3100:1 or wider among individuals and within a given individual over time. Assuming a true (and US legal) blood-alcohol concentration of .07%, for example, a person with a partition ratio of 1500:1 would have a breath test reading of .10% over the legal limit. Most individuals do, in fact, have a 2100-to-1 partition ratio in accordance with William Henry's law, which states that when the water solution of a volatile compound is brought into equilibrium with air, there is a fixed ratio between the concentration of the compound in air and its concentration in water but it is important to appreciate that this ratio is constant at a given temperature; very few "personal" breathalysers incorporate a temperature check in their software/hardware solutions. Breath leaves the mouth at a temperature of 34 degrees Celsius. To ensure that variables such as fever and hypothermia could not be pointed out to influence the results in a way that was harmful to the accused, most instruments are calibrated at a ratio of 2100:1, underestimating by 9 percent. In order for a person running a fever to significantly overestimate, he would have to have a fever that would likely see the subject in the hospital rather than driving in the first place. Thus, a machine using a 2100-to-1 ratio could actually overestimate the BAC. As much as 14% of the population has a partition ratio above 2100, thus causing the machine to under-report the BAC
How to use a Personal Breathalyzer
Although personal devices like the Alcohawk Slim 2 and Precision can never replicate the absolute reliability of something like a Dräeger 6510 (see "Sampling Methods" and "Sensor Types" etc below) they can be very useful when used over a period of time to generate a "picture" of how you absorb alcohol. Everyone is different, and factors such as the time taken drinking, the last time you ate and your own metabolic rate can all affect quite dramatically the rate at which alcohol is absorbed. It is impossible to simply equate 1 "unit" per hour, or any other simplistic statistic, and then guess your resulting level. A recent independent test carried out by the IOC newspaper group used one of our Breathalyzers to test a random sample of drinkers in Croydon one Saturday night, and the results showed just how wildly wrong people were in trying to guess their level of intoxication (for the full article, click here) Using a personal Breathalyzer on a regular basis means the user can build up a broad idea of the way in which they personally react, at a time when they are not going to go anywhere near a vehicle, and can help them to make sure they do not find themselves still over the limit "the morning after the night before"!
The way to get the most from your Personal Breathalyzer is to use it regularly and use it to monitor the change in your level of intoxication, rather than looking at a single specific reading.. Always wait at least 15 minutes after drinking or smoking (or you can damage the sensor) and then test yourself, trying to blow steadily and consistently (see sampling below) so that you blow the same each time. Take 3 tests, each approximately 2 minutes apart, and compare the readings; if one is substantially different to the other two, try once more. when you have three readings that are within a reasonable difference of each other, take an average and wait 30 minutes - then test again. Don't be surprised if the reading is not exactly the same every time - see Sampling, Sensors and Displays below) - carry on testing every 30 minutes until you get a zero reading. You may well find that the reading initially INCREASES, between the first few tests and the next - this is because it is taking time for the alcohol to be absorbed into the blood stream from your stomach. You will also probably find that the level does not drop by the same amount every half hour - this is one of the main reasons you bought your detector, to see how YOUR body reacts and how long it takes to absorb the alcohol.
Sensor Types
Traditionally Breathalyzers were all designed around a device called a Fuel Cell. These are relatively expensive to manufacture (often £200 or more just for the Fuel Cell) but are highly accurate and reliable over a wide range and Breathalyzers certified for evidential use (known in the US as EBT's) use these sensors. In order to produce a more economic device for personal and home use various semi-conductor based sensors have been developed, which use varying levels of software complexity to translate their readings into equivalent values such as BAC%, mg/l and Microgrammes. These sensors are more susceptible to drift (where the values produced gradually vary as the unit gets older and is used more often), saturation/contamination (for example if the user has been smoking or drinking recently) and variations in temperature but for general home use, provided some margin for error is allowed by the user, can produce some perfectly acceptable results. Semi conductor based sensors also have a narrower range of sensitivity and are more complex to calibrate (see below) so for Employers or Enforcement agencies, who must have a reliable and consistent reading over the full range of use, only Fuel Cell, EBT-approved devices like the ACS J5 and Dräeger 6510 are going to produce the required levels of accuracy and reliability.
Users should also bear in mind that the accuracy of a particular sensor quoted in the specifications has been measured under strict laboratory conditions immediately following calibration. Due to the variations listed above, and particularly the limitations of sampling, it is unlikely that such specific accuracy is likely to be obtained on a repeatable basis by the user "in real life" and sensor saturation with alcohol, or contamination with smoke during a test, can quickly destabilise the sensor software and lead to unreliable results. Anyone using a "personal" Breathalyser should leave a substantial margin of error and take into account general factors such as what and when they've been drinking - you cannot rely solely on a Personal Alcohol Detector to determine your level of intoxication!
Calibration
Many handheld breathalyzers sold to consumers use a silicon oxide sensor which are far more prone to contamination and interference from substances other than breath alcohol. The sensors require recalibration or replacement every six months. Higher end personal breathalyzers and professional-use breath alcohol testers use platinum fuel cell sensors. These too require recalibration but at less frequent intervals than semiconductor devices, usually once a year and they are far more robust when it comes to dealing with high concentrations, such as would be found (for instance) in a rehabilitation clinic. There are two methods of calibration - dry gas, and wet bath simulation and all Breathalyzers can only remain accurate for so long before they need to be "reset" - or calibrated - against a known benchmark concentration level of alcohol. Each method requires specialized equipment and factory trained technicians. It is not a procedure that can be conducted by untrained users or without the proper equipment. On the whole a personal detector will remain accurate provided it is used properly, but once consecutive readings start to drift by an unacceptable degree then it will need to be recalibrated. Regular recalibration (roughly every 6 months) also helps ensure the sensor stays within calibration range; once outside this range, it cannot be reset.Some semiconductor models are designed to allow the sensor module to be replaced without the need to send the unit to a calibration lab however as replacing the sensor does not test the unit itself "in situ" this method is not as reliable as having the unit properly serviced by a trained technician.
Fuel Cell devices will generally "hold" their accuracy for longer, however because they are usually in use in an evidential environment most companies have them calibrated at least every six months. Dry gas calibration can only be carried out on Fuel Cell devices and is generally done at a single concentration level. Fuel Cells have a much more linear detection range the semi-conductor based sensors and as such are able to "predict" accurately both lower and higher concentrations from a single calibration point. The advantage of dry gas calibration is that little or no expertise is required to operate the equipment, and large-scale operators such as the police are able to have their own in-house setup in order to regularly check and calibrate their detectors. If the readings are not what you expect, first try re-testing on several occasions to see if blowing technique is an issue - see "how to use a personal Breathalyzer" and "sampling methods" above
Semi-conductor devices on the other hand are calibrated using wet-bath simulators, which is a device containing water, mixed with pure alcohol at a precise level and heated to an exact temperature. A minimum of two are required, and a Customs & Excise licence is required to purchase and store the materials. Semi-conductors have a much narrower, and less linear, range than fuel cells and so are usually calibrated at two points - a "low" level and "high" level just above and below the expected key point of use - in the UK, either side of the drink drive limit of 0.08 BAC%. The software in the unit then compares these two fixed points from the air supplied by the wet bath simulator and uses them to forecast other readings up and down the range. The problem however is that it is relying on the software to predict the results, and the non-linear nature of the sensor means it can only do so to within certain limits, particularly at very high (more than 0.20 BAC%) or very low (less than 0.02 BAC%) levels. For personal use, as a general indicator of changes in the level of intoxication, semi-conductor based Breathalyzers are very useful devices but users cannot put too much store by any one specific reading and must allow reasonable margin for error