Bubble Flowmeters are the most common device for measuring a volumetric flow rate. The Flow is determined by measuring the time required for a gas stream to move a soap bubble through a specific volume.
J&W Scientific Digital Flowmeter, measured in L/min. Verify mass flow controller settings, or monitor higher gasflow rates. Runs on 9 volt battery.
Humonics Optiflow 520 Digital Flowmeter. Flow rate 0.5-500 ml/min. Powered by 9v battery.
Humonics 1000 Digital Flow meter, flow rate 1-30 mL/min. A microcomputer and infrared optics are used to track a rising volume of liquid within a tube of precision-bore glass. Absolute accuracy is established by comparing the performance of the instrument to an NIST-registered burette.
Hewlett Packard Digital Flowmeter 9301-1004, measured in mL/min