Next-gen air flow sensors with enhanced protection for medical applications

Posifa Technologies has launched the next generation of its mass airflow sensors for respiratory care and other medical and instrumentation applications. Created to give an extra level of protection for reliable performance in severe environments with high humidity and trace amounts of corrosive gases, the new PMF83000 and PMF86000 series sensors have been enhanced with a parylene coating over the complete PCB assembly — including the sensor die.

The sensors serve as key components in ventilators, respirators, nebulisers, oxygen concentrators, and CPAP equipment, where they control the volume of airflow to patients. Also, the devices give mass flow measurement in anaesthesia delivery, fuel cell control, and environmental monitoring equipment.

The series features the company's third-generation thermal flow die, benefiting from the latest innovations in microfabrication. The sensor die utilises a pair of thermopiles to identify changes in temperature gradient caused by mass flow, producing excellent signal-to-noise performance and repeatability of 0.5% F.S. Both series highlight a single main flow path design, excluding the risk of the bypass being clogged by water condensation and dust particles.

Measuring flow rates from 15SLM to 100SLM and 50SLM to 300SLM, respectively, the series provides remarkably fast response times of 5ms typical and work over temperature ranges of -25C to +65C. The devices give analog (voltage) and digital I²C outputs in the same package and support bidirectional flow measurement.