1. Same as the calibration method: fully open the piston (for a stopperless burette, the glass ball must also be forcefully squeezed) to allow water to fully flow into the collection bottle from the flow port. When the liquid level drops to about 5mm above the calibration line, wait for 30 seconds, then adjust the liquid level to the calibration line within 10 seconds, and then use the collection bottle to remove the last drop of water from the flow port.

2. The same as when in use: a liquid discharge speed of 6-8mL/min. When the liquid level drops to about 1mm above the calibration line, wait for 30 seconds, then adjust the liquid level to the calibration line within 10 seconds, and then use a collection bottle to remove the last drop of water from the liquid flow port.