There are a number of ways officers in Arizona might choose to test whether or not you have been driving under the influence of alcohol. For example, you could be asked to participate in a number of field sobriety tests designed to assess your responsiveness and coordination. If you struggle with the tests, officers may assume you are suffering from impairment due to intoxication.
The most widely known method of determining drunkenness, however, is the use of a Breathalyzer. This device is designed to measure a person's blood alcohol concentration by analyzing a sample of their breath. If the BAC reading is equal to or above the legal limit of 0.08 percent, that person is deemed to be intoxicated and may be charged with driving under the influence.
Concerned about the consequences of an incriminating reading, some choose to refuse the Breathalyzer test. This can be a tempting choice if you suspect that you may be over the limit. However, it is important to remember that refusal can result in the revocation of your driver's license.
Another thing to bear in mind, as this article on DUI investigations explains, is that officers might still obtain a warrant to take a blood sample from you. However, this could be reassuring if you were concerned about inaccurate readings from the Breathalyzer as a blood draws tend to yield more accurate results.
However you choose to proceed, criminal charges are always worrying. If you find yourself in this difficult situation, you might benefit from the advice of an attorney. He or she can assess the circumstances of your arrest and may be able to help you challenge the evidence being used against you.