How the Intoxilyzer 8000 Is Used
Oregon uses the Intoxilyzer 8000 to approximate a person’s breath alcohol content (BAC). In conducting the test, the officer will take two breath test samples from you. The samples should be taken 3 minutes apart. The lower number is accepted and is truncated to 2 digits.
Determining a Valid BAC Test Result
Sometimes the samples are not exactly in agreement. Oregon Administrative Rule 257-030-0140 establishes the criteria for when two samples create a valid result. Agreement between two valid breath samples within a testing sequence is established when the subject sample measurements agree within plus or minus ten percent of their mean.
Thus, a test in which a first sample results in a 0.20 and a second result of 0.15 would have a mean value of 0.175. Since the subject samples are 0.15 and 0.20, the mean is 0.175. Agreement within 0.157 to 0.192 would be 10% of the mean. Since the samples are outside of the range established within 10% of the mean, this would not be a valid test result.
However, a sample of 0.193 and 0.178 would give a mean value of 0.185. Within 10% of the mean would be 0.166 to 0.203. Now both samples are within 10% of the mean and this would be considered a valid sample. The lower number would be used for the result. The lower number would then be truncated to 2 digits and produce a BAC result of 0.17 and be considered a valid result.