There are administrative rules governing evidential breath test instruments that are used in drunk driving OWI cases. Any officer administering such a test must be properly trained and such instrument shall only be operated by an appropriate class operator pursuant to 2010 AC, R 325.2658(4). There are six classes of operators for preliminary breath tests (PBT) and evidential breath tests such as the DataMaster. The class of operators are: Class I, Class II, Class IIIA, Class IIIB, Class IVA, and Class IVB. The lowest level Class I operator is only qualified to administer the PBT or the roadside breath test. Class II through Class IVB can administer the evidential breath test at the police station which is usually the DataMaster. The Class IVB operator is the only one qualified to perform the 120-day maintenance check and the calibration or any maintenance on the DataMaster.

To be classified as operators, the officers must take training on each class they wish to be qualified for. This training usually consists of one day for each one. Class I operators receive two hours of training for the PBT, Class II receives six hours of training, while the remaining classes are eight hours each. It is always important in any DUI case to verify that the operator is certified to perform the functions that he did in the case at hand and if the operator's certification is current.

An evidential breath test analysis must be on specific forms that the police department approves. The OD80 is the breath alcohol content form. Your OWI attorney should carefully scrutinize for any missing detail or information on the form. The start time for the observation period should be carefully compared with the breath room video to make sure they correspond. There is a mandatory 15-minute period that the officer must observe the suspect before administering the breath test. This is to make sure that the suspect does not regurgitate, smoke, or otherwise place anything in the mouth during this time period because any of these instances could mess up the reading of the machine. That doesn't mean the officer has to stare directly at the suspect non-stop for 15 minutes. As long as they are in his peripheral vision that will suffice. If he turns his head for a significant amount of time or leaves the room or clearly isn't paying attention, then that is a violation that can get the results of the breath test suppressed.

A blank sample is done first to test that the machine is working properly. Usually two breath samples are performed although only one is necessary. The second sample is to merely confirm the first sample by making sure its variance is within the acceptable range or margin of error which is essentially 10%. In other words, if the first result was .10 and the second result .11, that is acceptable. If the first result was .10 and the second result .13, that would not be acceptable. The officer can do a third sample but at that part it's too easy to argue the machine was not working properly. 

The DataMaster must also be inspected weekly on a log sheet known as the OD33 and there must be separate log sheets for each month. The supervisor must sign the logs at the end of each month. It's important that your DUI attorney check the calibrations on the logs to make sure they are within the acceptable range. Also, only certain mixtures that are pre-certified by the department can be used to test the machine. It is important that the mixtures (lot numbers) used is an approved lot number and that it hasn't expired as they do have shelf lives. The PBT must be calibrated monthly.

In order for any chemical test to be admitted into evidence, essentially the prosecution must prove three things: 1) the operator of the chemical test was qualified, 2) the proper method was used, and 3) the testing device was reliable.

This is a very complex and scientific area of the law and each requirement and each stage is critical. That is why it is extremely important that each procedure and rule must be scrutinized carefully to make sure everything was done properly by someone with the proper training to do so. Otherwise, the results could be inaccurate which can lead to false convictions. If you have been charged with OWI, make sure you have an experienced OWI lawyer representing you.