Q. What is a BreathalyzerTM and how does it work?
A. Without question, the BreathalyzerTM is the breath testing device of choice in the State of New York. Often an aesthetic disappointment to those who see it for the first time, the BreathalyzerTM 900A is housed in a bland metal box 8 ½ inches by 9 inches by 10 ½ inches, and weighs about 13 pounds. Developed by R.F. Borkenstein, the Model 900A and its predecessors have been on the market since 1954. For many years these devices were manufactured by Smith & Wesson. In July of 1984, Smith & Wesson sold its BreathalyzerTM division to National Draeger, Inc., the American subsidiary of a German concern. National Draeger has continued to manufacture BreathalyzerTM Models 900 and 900A, and also a device using infrared absorption technology, the Model 7110.
The instrument is composed of three basic sections:
- A breath sample collection system;
- A chemical reacting system consisting of glass vials (ampoules), containing a chemical solution sensitive to alcohol. This solution is called a reagent (pronounced ree-A´-gent);
- A photometric system consisting of a light source, two photo cells (devices that convert light into electrical energy) and a meter, which measures differences in electrical current between the two photocells.
Employing a wet chemical process in the so-called ampoules, the model 900 and 900A, are generically known as "visible light photometers." In the most basic terms, they simply depend upon a visible color change in the vial of wet chemicals, which change is then measured by the variation in the amount of light that is permitted to pass through the presumably clear glass vial.
Q. How does a Breathalyzer collect breath?
A. From a plastic tube, the sample is delivered into a cylinder in which a piston is located. A thermostat inside the instrument keeps the temperature in the cylinder at 50°C plus or minus 3° (approximately 122°F). Located on the top of the instrument is a temperature gauge visible to the breath test operator. The chamber is designed to trap and deliver to the test ampoule exactly 52.5 milliliters of deep lung air. To accomplish this, it must trap more than that (56.5 milliliters); the remaining four milliliters remain in the tubing between the chamber and the test ampoule, somewhat like that last bit of toothpaste that remains in "dead space" of the tube after all the usable toothpaste has been pushed out.
Temperature is critical: If it is too low the test result will be falsely high, and if too high, falsely low. Because the BreathalyzerTM is designed to measure deep lung air-the last portion of the subject's expiration-the chamber is designed to discard all but that last portion of breath by allowing it to vent into the room through vent holes in the sides of the cylinder.
Q. How does the BreathalyzerTM test the breath for alcohol?
A. The alcohol is actually "tested" in thin-necked glass containers we've called ampoules. These ampoules contain the reactive chemical solution. They must contain exactly the correct total amount of chemical solution. Too much will have the effect of diluting the chemical reaction with the breath sample, resulting in a falsely low test result; too little and the result will be falsely high, for the opposite reason. The three milliliters of solution within each ampoule contain a solution of 50 percent by volume sulfuric acid, .025 percent potassium dichromate, and .025 percent silver nitrate, with the remainder distilled water. The sulfuric acid acts as a desiccant, a substance that absorbs alcohol. The silver nitrate is a catalyst that speeds the reaction without itself being changed. The two ampoules used in the test are in a sealed condition at the start of the test. The reference ampoule remains sealed throughout the test. The other ampoule is broken at the neck. A glass "bubbler" is then connected to the delivery tube leading from the sample chamber. The bubbler is inserted into the test ampoule. The effect is to create a system of tubing that will carry the breath from the sample chamber into the test ampoule. When the chamber is filled, the operator manually rotates a control knob on the top of the instrument from the "Take" position to the "Analyze" position. This permits the sample to be forced from the piston into the test ampoule. When viewed, the ampoule solution has a pale yellow color roughly akin to weak lemonade. If breath containing alcohol is passed through the ampoule solution, the solution will lighten or bleach. A light bulb is placed between the two ampoules. On the outside of the ampoules photocells are mounted to measure the light which passes through each ampoule. At the beginning of the test, the electrical output of the photocells is fed to a meter. If the needle stands in the middle of the meter it is balanced. If alcohol passes through the ampoule and the color of the ampoule lightens, more light will strike the photocell. This will cause the meter needle to move to the left. The operator then "balances" the machine by turning a knob on the outside of the machine. This simultaneously causes the light to move away from the test ampoule and the needle to move toward the center. It also causes a large pointer on an alcohol scale on the top of the machine to move to the right. When the electrical needle has moved to the center, the operator checks the pointer. The pointer should then indicate the amount of alcohol in the persons blood.
Q. Does this mean the operator actually "sets" the result?
A. It does.
Q. Could it be set falsely high?
A. It could. In our experience at Fiandach & Fiandach we identified at least one situation where operator falsification may have occurred. Further, such has been substantiated in the literature.
Q. If I believe this happened, how can I prove it?
A. This is an extremely complicated topic. To prove operator falsification you must seek the services of an attorney who is knowledgeable on this subject.