The instrument for measuring atmospheric pressure, the barometer, is calibrated to read zero when there is a complete vacuum; the pressure indicated by the instrument is therefore called absolute pressure. The term pressure gauge is commonly applied to the other instruments used for measuring pressure.
They see what's already there in a different way, and most of the time, they're aware that their altered perceptions are caused by the drug. After taking LSD, the effects -- known as a trip -- usually start within an hour and can last up to 12 hours, with a peak about halfway through the experience.
Now for the time visitors spend on site. Average Session Length (ASL) measures the average amount of time a visitor spends on your site or on a particular page. If you got 4,000 visitors this month and they spent a total of 29 hours on your site, the average session length was 26.1 seconds.ow for the time visitors spend on site. Average Session Length (ASL) measures the average amount of time a visitor spends on your site or on a particular page. If you got 4,000 visitors this month and they spent a total of 29 hours on your site, the average session length was 26.1 seconds.