Harris count probation test is usually for alcohol consumption. Alcohol start to excrete from the system within one hour of drinking and no alcohol is present in system in the next few hours. But one metabolite of alcohol called ethyl glucuronide can be detected in the urine for 80 hours. This test is called EtG urine test. This test does not tell amount of alcohol consumed but can tell that the person has used alcohol in the last 4-5 days. This test is more reliable than other alcohol tests.