A rugged aerospace-grade differential pressure (DP) sensor from Kavlico monitors pressure drop across a turbine engine-style inlet air filter by detecting increases in pressure across the filter element. The pressure difference increases in proportion with the amount of filtrate captured by the filter. The DP sensor provides a continuous measure of filter health, with a predetermined pressure difference used to indicate critical airflow restriction by the filter. In applications where the sensor indicates the airflow has been critically restricted by a clogged filter, an inlet bypass can be opened to maintain flow to the engine until filter maintenance can be performed. The sensor incorporates a piezoresistive sense element and comes in pressure ranges of 0-1, ±1, ±5, and ±10 psid, with other options available.