5-second test for the most common pipette failure modeUses vacuum to maintain pipette hygiene4 attachments for tips from 1 L to 1000 ml and upReplaceable air filterLeak test. Most failures are due to damaged seals, O-rings, pistons or tip-holders. The AD-1690 tests by creating and measuring a vacuum. No contaminants or dust enters the pipette because air is evacuated from the pipette.