Flowmeter; Dry Gas, 2-20 SCFH, 2'' Scale, Brass Valve, w/TUI logo, for 4- to 10-Chamber Desiccators 1600-32 | Terra Universal
Amazon.com: Gas Flowmeter, LZQ-7 1-10LPM Unidirectional Flow Meter Oxygen Tester with Control Valve for Nitrogen, Air, Gas, Hydrogen : Tools & Home Improvement
GM1 Series - Nitrogen Mass Flow Meter - Aluminum, Low Flow, With or Without LCD Readout, 1/4 Inch Compression Fittings, 0-5VDC Analog Output