San Diego DUI Breath Test

An analysis of your breath using a “breathalyzer” (police will often administer this test immediately on the road) gives only an indirect value of a blood alcohol level.  This type of test is based on the level of alcohol in proportion to exhaled air, not the amount of alcohol that is in the blood.

In order for this type of apparatus to calculate the blood alcohol level from exhaled air, the content of alcohol in the air is multiplied by the number of 2,100.  The number 2,100 is known in the equation as a “partial ratio” (coefficient) and is used because an “average” persons lungs can exhale air usually at 1/2100th the amount of alcohol of an equal volume of blood. 

By using this average figure amount it amounts to a little more then just scientific guesswork.  As a matter of fact, this value can fluctuate for the same person tested over a period of time and depends on a person’s body temperature and then his/her respiration rate.  For these reasons, the amount of a persons Blood Alcohol Level (which is either displayed or printed out on a device) may be inaccurate and wrong.

Alcohol-containing products or substances in the mouth have also shown that they may produce falsely high or erroneous readings, since the amount of alcohol residual or vapor they release can be much greater than the amount exhaled from the lungs.  This can also include stomach fluid or bile vomited or regurgitated for up to 20 minutes of administrating the breath test, some types of toothache medicines, mouthwashes and even breath fresheners may contribute to higher results in some cases. In some cases even burping just before of while the test is being given may give a falsely high reading in the tube.  For this reason the general policy is that the person administering the test is suppose to observe the subject for a period of at least 20 minutes prior to giving the breath test to observe that the subject does not burp, belch, vomit, or regurgitate, or put any foreign substance into their mouth.

Because there is also the possibility of the malfunction of a breath-testing device, to assure the accuracy and the device is operating correctly the breath-testing device must be frequently calibrated with air containing a known amount of alcohol.  The police department should keep detailed records on file showing how the device in question has been calibrated, serviced, and used.

Finally, because the breath gas analysis (breathalyzer) can be found to often be inaccurate the subject may be instructed to take the test a multiple amount of times to try and produce a consistent result.  If the subject fails to give the police the samples they are requesting then the subjects drivers license might be suspended for a period of one year for not complying.

DUI Blood Test

The most accurate test that is currently available to measure a person’s blood alcohol level or to test for drugs is a blood test.  At Ross Law Center we look for and discover possible problems with the testing of the sample based on the chemistry that is involve in the analyzing of the blood.  For example, we have found that some blood samples may not be properly preserved and may sit for unusual long amounts of time before being tested thus the samples may begin to decompose or coagulate and this may lead to false or high readings.

In addition, many laboratories that test and analyze blood or even urine samples run numerous test samples every day, with different parts of the test being carried out in different bottles or beakers.  This could also lead to errors in some samples and particularly if the lab responsible for testing the samples does not follow the proper record keeping implemented by the testing facility or its organizational procedures are not carefully followed.

Most chemical analyses of a drivers blood or breath will give an accurate indication of a persons Blood Alcohol Level (BAC), however, the tests are not infallible.  The experienced attorneys at Ross Law Center may be able to cast enough doubt on borderline test results thus helping our clients to achieve the best and most favorable results through a settlement or even trial if necessary.

Call Ross Law Center today to discuss your case or schedule a free initial consultation to review your case.  The Ross Law Center is dedicated to the field of Criminal Defense only and can help you in your DUI case.