Airflow Measurement in Electronics 
Board Mount Series Part 2: 
Airflow Measurement for Filter Clog Detection

Note: Part 3 of our Board Mount Series – Load Card Testing with Airflow and Temperature Sensors explains how thermal load boards help to improve system performance and reduce development time of complex electronic assemblies.  

Fan cooling is an efficient way to keep electronics cool in enclosed spaces, and fan filters help prevent the intrusion of contaminants that could damage those electronics and circuitry. Fan filters perform well, as long as they are not clogged or damaged. Clogged filters have reduced performance and obstruct airflow, leading to increased system temperatures. Measurement of air velocity within dense electronic systems and enclosures is essential, as premature component or system failures may result when typically tight thermal margins are exceeded.

Degree Controls has the tools available to address the need to measure and monitor airflow within dense PCBAs in enclosed spaces. Our F66x board mount digital air velocity and temperature sensors use dual element sensing technology and can be directly soldered or socketed to your PCBA to manage clogged filters and air flow intake and exhaust disruptions.

The F66x board mount air velocity sensors can be used inside electronic systems to: 

• Augment existing temperature-based environmental sweeps on board assemblies

• Track fan air filter health over time 

• Provide watchdog functionality for accidental airflow blockage

ensuring that filtration performance and the supply of air is not compromised. If air is not moving optimally, the user is alerted to the fact that the fan’s air filter is clogged. 

Airflow measurement with these integrated board mount sensors enables maintenance alarms, signaling when it’s time to take action to clean or replace a filter, and provides a means for additional control, such as changing fan speed or making shutdown decisions. Air velocity and temperature data logging can also provide protection against early product failure liability. 

Digital Output for Communication, Control and Alarm

The F66x board mount sensors measure air velocity and air temperature inside electronic systems in real time, and communicate across the I2C or UART bus. Sensors can be operated as monitor only, sharing velocity and temperature data with the system controller, or as a closed loop fan controller with PWM output. In addressable, multi-sensor deployments, air velocity across an area or volume can be measured at multiple locations. F66x board mount air velocity sensors can also be configured to function as a switch and provide an alarm output.