THC means tetrahydrocannabinol, which is present in Marijuana cigarettes. The single dose of tetrahydrocannabinol is completely eliminated from body after 30 days through urine. But it will take 100 days to be eliminated from your hair follicles.
Every test result sheet from a drug testing lab should show the tested levels compared to the legal limit levels of any drug that caused a positive result. So if you have all the results sheets it should show that with each subsequent test following the first positive result, the THC level reading should be lower than the previous test. As long as your numbers are declining the probation officer should understand that you are no longer using.
Yes it can be detected on how much is in your system even when no longer using by doing a urine lab test in which it test the level of thc in system.... My p.o is currently lab testing me after failing a dip strip test to ensure my using has stopped.... Based upon body fat in person thc can be traced in system up to 3 months or longer