About SKC Terms of Use Privacy Policy Careers
© Copyright 2020 SKC Inc. ISO-9001
TrainingMy AccountMy FavoritesCart

Soap Film Flowmeters

Orderable Items Soap Film Flowmeters are easy to use for calibrating sample pumps. SKC offers two models that are calibrated to within ± 2% of the volumes marked on the flowmeter and are supplied with a certificate of calibration.

  • Easy to use

  • Sample contacts only glass and stainless steel

  • Calibration lines encircle the tube for easy reading




Principle of Operation
The operating principle of the SKC Film Flowmeter is simple: the sampling pump to be calibrated is attached to the top of a volumetric glass tube containing a small amount of liquid soap. As the pump draws air through the tube, a flat soap bubble is interposed in the flow path. While the air flow causes the soap film to move from one volume mark to another, the travel time is measured with a stopwatch. The flow rate can then be directly calculated using the travel time and the known tube volume, or it can be read from the flow chart. The test is quick and easy to perform. With a film flowmeter, flow rates are based upon the inherent, unchanging properties of the measuring apparatus. The 303 Portable Flowmeter and the 311 Laboratory Film Flowmeter kits are calibrated to within ± 2% of the volumes marked on the flowmeter and are supplied with a certificate of calibration.

Model 303 Portable Field Flowmeter Kit
Range: 5 to 500 ml/min
The SKC 303 Portable Flowmeter Kit contains all of the equipment, except a stopwatch, required for calibrating low flow pumps typically used for sorbent tube sampling. The complete kit weighs only 3 pounds (1.4 kg) and includes a 100-ml buret flowmeter, film solution, operating instructions, flow charts, and a removable carry case. Calibration lines for 90, 95, 105, and 110 ml are also on the buret; allowing for the calibration of detector tube pumps.
303 Flowmeter
Pump Calibration Train with 303 Flowmeter
303 Flowmeter
303 Flowmeter with Pump Calibration Train


Model 311 Laboratory Film Flowmeter Kit
Range: 300 to 3000 ml/min
311 Flowmeter  
Closeup of 311 Flowmeter Sidearm for Pressure Sources
311 Flowmeter  
311 Flowmeter side arm for pressure sources

The SKC 311 Laboratory Film Flowmeter Kit consists of a glass tube with red calibration lines at specified volumes, a squeeze bulb to contain sufficient soap film solution for flow measurement, an adapter to accommodate either vacuum or pressure sources, a stopper and connecting tubing, a tripod stand, film solution, and operating instructions. The SKC 311 Laboratory Film Flowmeter Kit provides quick and accurate flow determinations at specified flow rates.

About Built-in Flowmeters and Rotameters
The ball-type flowmeters and rotameters built into most air sampling pumps are primarily intended to serve as flow indicators and are, therefore, of low accuracy. These flowmeters as well as rotameters must be calibrated against a primary standard such as a film flowmeter or electronic calibrator to verify accuracy.