FMA-1600A and FVL-1600A are high-quality flowmeters that make use of the differential pressure principles in order to determine their mass flow rate. The operating principle for these devices is a fairly simple one. An LFD (Laminar Flow Element) is placed inside the meter and has the role of forcing the gas into laminar flow. Next, the volumetric flow rate is dictated by the Poiseuille equation, while the viscosity of the gas can be used to determine the volumetric flow rate. The sensors for pressure and absolute temperature are placed separately in the unit, according to the design, while the mass flow rate can be reported in units such as SLM (standard liters per minute) or SCFM (standard cubic feet per minute).