Accuracy, Reliability, Integrity.

Our innovative Flow Averaging Tubes™ (FAT) directly calculates mass flow using convective heat transfer and is best suited to most applications with a limited straight run. The upstream straight run can be decreased to three diameters in many systems. Along the length of the upstream impact surface, the probe contains several large diameter entrance openings. The pressure at each entrance port is averaged inside the tube to produce the axial flow through the tube and over our flow sensor. The gas returns to the main flow stream through the ports near the detecting devices. Minor adjustments may be required to attain the best accuracy if there are anomalies in the real flow profile or installations in non-circular ducts.

Thermal mass flow meters detect mass flow directly using the convective heat transfer theory. Two ratiometrically matched, reference-grade platinum Resistance Temperature Detectors (RTDs) are used in EPI's unique thermal mass flow sensors. The platinum sensing element wire is encased in a 316 Stainless Steel sheath or a Hastelloy C sheath if one is required. Our intelligent sensor technology, which is controlled by a microprocessor, preferentially warms one RTD. At the same time, the other serves as a temperature reference. The heat from the first RTD is dissipated by the process gas flow, increasing the power necessary to keep an equilibrium between the RTDs. This rise is proportional to the molecular rate of flow of the gas. Our sensors are temperature adjusted for a wide range of process gas temperatures. As a result, they are unaffected by pressure fluctuations, resulting in a real mass flow rate indication of the output signal.