Digital thermal mass flow-meter
FMA-1600A OMEGA

The FMA-1600A and FVL-1600A Series mass and volumetric flowmeters use the principle of differential pressure within a laminar flow field to deterime 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 standardised flow rate is commonly called the mass flow rate and is reported in units such as standard cubic feet per minute (SCFM) or standard litres 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 teperature can be viewed or recorded through the RS232 connection. It s also possible to multi-drop up to 26 units on the same serial connection to a distance of 38 metres. These flowmeters can be powered by the optional battery pack FMA1600-BP for use in the field.
The FVL-1600A Series comprises volumetric flowmeters only. They do not measure or correct for absolute pressure or temperature. The FMA-1600A Series is recommended if the operating pressure is above 10 psig or if there is any restriction or backpressure in the applications.