The model W-NK Wet gas meter is a net-volume type integrating flowmeter that employs a drum as the metering element. As the drum is sealed with water or other fluid, the model W-NK provides the measurement of any gas irrespective of the gas specific gravity and viscosity. Further, since this gas meter permits the measurement of very small flows, exhibits high reproducibility, and offers various other excellent features, it properly serves as a standard as well as a testing instrument.