Soap Bubble Flowmeter

Soap bubbler flow meters are a classic method for measuring the gas flow rate for carrier gases in applications such as gas chromatography (GC). The unit is supplied with a rubber bulb which attaches to the bottom of the device. The outlet of the system to be measured is connected to the serrated hose connection (9 mm O.D. at the middle ring, 10 mm O.D. at the largest ring), and the bulb is partially filled with soapy water.

To make the measurement, the user squeezes the bulb until the soapy water goes above the gas sidearm. This will cause a series of flat soap film bubbles to rise up the calibrated column. Simply time how long it takes for the bubble to travel a given volume to determine your flow rate. The column is open at the top and a clever projection at the top breaks the bubbles automatically.

This item is available in 10 and 25 mL sizes. The 10 mL has 0.05 mL subdivisions and the 25 mL has 0.1 mL subdivisions.

10 mL dimensions: Overall length (without bulb): ~12-5/8" (322 mm). Width at sidearm: ~3" (76 mm). Tube diameter: 7/16" (11 mm).