The FMA-1600A Series mass and volumetric Omega’s flow meters use the principle of differential pressure within a laminar flow field to determine the mass flow rate. A laminar flow element (LFD) inside the meter forces the gas into laminar (streamlined) flow. Inside this region, the Poiseuille equation dictates that the volumetric flow rate be linearly related to the pressure drop along a fixed distance of the LFE. This, along with the viscosity of the gas, is used to accurately determine the volumetric flow rate. Separate absolute temperature and pressure sensors are incorporated and correct the volumetric flow rate to a set of standard conditions. This standardized flow rate is commonly called the mass flow rate and is reported in units such as standard cubic feet per minute (SCFM) or standard liters per minute (SLM).

Standard units include a 0 to 5 V output (4 to 20 mA optional) and RS232 communications. The gas select feature can be adjusted from the front of the keypad or via RS232 communications. Volumetric flow, mass flow, or absolute pressure, and temperature can be viewed or recorded through the RS232 connection. It is also possible to multi-drop up to 26 units on the same serial connection to a distance of 125′. These flowmeters are also available in a portable version for use in the field (-B models).