If you get pulled over by a police officer, he or she may give you a breath test and/or make you do field sobriety tests to determine if you are under the influence of alcohol. These tests can be enough to warrant an arrest.
However, you may then be given other types of tests in a lab setting to further establish if you were under the influence of illicit substances. These could be blood tests, urine tests and the like.
One important question to ask is how often these testing devices have to be calibrated and checked for accuracy. If you are given the tests without the proper procedures being followed, it could skew the results and leave you facing unfair charges.
Under Ohio law, the "analytical techniques or methods" need to be calibrated and checked every single testing day. If a day gets skipped, even if everything worked properly 24 hours before, that could call the results into question.
Furthermore, the calibration needs to be done "under the general direction" of the person who runs the laboratory. This director, however, does not always have to be physically in the room during the check. They just have to generally oversee the process. This is also important because failure to do so could likewise call the results into question.
If you think that the test results you got were not accurate, no matter what type of test you were given, it is crucial that you understand all of the legal options you have to protect yourself from the charges stemming from those test results.