An air flow hour meter is provided. The air flow hour meter includes a passage configured to receive a pressurized fluid flow therethrough. An obstruction in the passage can be positioned in the fluid flow. A sensor in communication with the fluid flow can be configured to measure a pressure differential of the fluid flow between a first point and a second point of the passage. A microprocessor can be configured to calculate the signal-to-noise ratio of the sensor, and a timer can be configured to activate when the signal-to-noise ratio falls below a predetermined limit and otherwise deactivate.