Breathalyzer vs. blood test

Although there are several methods to test the level of alcohol in the blood of a person, the two most common are the measurement of alcohol in the breath and blood alcohol content. Police departments throughout the country mainly use these two methods within investigation of potential drunk drivers. Each method has its own strengths and weaknesses, and learn about the differences can help determine the best test method for your needs.

Test methods

Both breathe tests like blood and measure the same: the amount of alcohol found in the blood stream. The two methods reach measuring different forms. The blood test directly measures the amount of alcohol in the blood. Breath tests estimate the amount in the blood by measuring the amount of particles breath alcohol.


No method is particularly profitable, though there are definitely differences in cost between the two. The breath test has a fairly high initial investment, as a device breath test only a Breathalyzer can cost as much as US $ 10,000. Add to that the cost of adequate training of operators and technicians, and the cost of equipping a police department with the instruments can be prohibitively expensive is added. Once the initial costs have been absorbed, breath tests become much less expensive.

The costs of maintenance are relatively minor, since repairs and periodic calibration can be made ​​for a fraction of the initial cost. Blood tests are much more expensive on the basis of tests per test. Each blood sample must be taken by a person and sent to the state department of crimes or independent private laboratory for analysis. The blood test is the test method more expensive alcohol.


Testing blood alcohol is the most invasive method alcohol testing. A qualified technician actually draws a blood sample from your arm. The technician must be able to find a vein; bruising and needle are not uncommon. The breath test is completely non-invasive. You simply exhale into the device and you measure the alcohol content in the breath. Consequently, many people are more wary of giving consent to a blood sample of what they do with a breath sample. Police do not usually ask for a blood sample unless they have reason to believe that there may be something in your system, such as drugs, which cannot be measured by a breath test.


Both test methods are highly accurate, but the blood test is the most accurate way to measure alcohol content method. While the sample is taken and stored properly, and not contaminated in any case, positive test result is accurate. Breath tests are very accurate, but may present some problems. The test subject must provide an adequate sample of breath for the instrument to obtain a correct measurement.

The additional radio interference outside or other electronic devices can interfere with the instrument. The device must also be properly calibrated and tested regularly to ensure you are reporting accurate results. Finally, certain substances, such as washing the mouth, can cause the instrument of a false positive result. Modern breath test devices have internal safeguards to prevent an outcome if not everything is perfect, but there is still more room for error. A breath test will be maintained and managed essentially as accurate as a blood test, but it does provide more opportunities for user error or incorrect results.


Both tests and blood alcohol test breath alcohol are equally admissible in a court of law in most states. For a breath test, the prosecution is required to prove that the test was administered correctly and that the equipment was working properly. For a blood test, the prosecution must prove that the sample is taken and stored correctly and could not have been manipulated. While these basic requirements are met, both tests are equally admissible and are supposed to be equally accurate.