Next-generation air flow sensors

Posifa Technologies has announced its new PMF8300 series of mass air flow sensors for use in respiratory care and other medical and instrumentation applications.

The PMF8300 series devices offer improved accuracy, repeatability, and signal-to-noise performance, compared to previous generations of the sensor.

Compact and robust, the sensors serve as key components in ventilators, respirators, oxygen concentrators, nebulizers, and CPAP equipment, where they control the volume of air flow to patients. In addition, the devices provide mass flow measurement in spectroscopy and environmental monitoring equipment.

According to Posifa, the PMF8300 series is a cost-effective upgrade for new equipment designs and due to the devices' simplified design, it will be possible to scale up production of the PMF8300 series rapidly in response to sudden surges in demand.

The PMF8300 series sensor features Posifa's third-generation thermal flow die, benefiting from the latest innovations in microfabrication. The sensor die uses a pair of thermopiles to detect changes in temperature gradient caused by mass flow, delivering excellent signal-to-noise performance and repeatability of 0.5 % F.S.

The 'solid state' thermal isolation structure eliminates the need for the surface cavity or fragile membrane used in competing technologies. The sensor die, with its silicon carbide protective film, is robust against water condensation while allowing the highest level of sensitivity and minimizing the cost of packaging.

Measuring flow rates from 15 SLM (PMF8315) to 100 SLM (PMF8399), the PMF8300 series offers extremely fast response times of 5 ms typical and operates over a -40 °C to +85 °C. The devices provide both analogue (voltage) and digital I²C outputs in the same package and can be customised with bidirectional flow sensing.