What is the different between a drunk driving field sobriety test and a drunk driving chemical test?

A field sobriety test in California is used to determine probable cause for DUI arrest. The field sobriety test is actually a series of drunk driving tests given by a police officer on the side of the road before an actual DUI arrest is made and a person is brought back to the police station. It should be noted that the results of any hand-held digital breathalyzer test given during a field sobriety test (on the side of the road) cannot be used in court to prove DUI. These road-side breathalyzer tests are only used to help prove probable cause for DUI arrest in California but their results are not accurate enough to be used in court. A chemical DUI test is required after a California DUI arrest is completed. These tests happen at the police station are either alcohol blood tests, alcohol breath tests or sometimes alcohol urine tests. Alcohol urine tests have been shown to be somewhat inaccurate so they are only used if a DUI blood test or a DUI breath test is unavailable.  more