Aspirated Radiation Shield

Apogee Instruments, Inc. (Apogee)

The fan has an ingress protection (IP) rating of 55, virtually eliminating moisture and dust ingress. At full speed the power requirement is 1 W (80 mA at 12 V DC). To conserve power fan speed can be reduced, via pulse width modulation (PWM), to 0.3 W at night or when wind speed is greater than 3 m s-1 without loss of accuracy. If the fan is continuously operated at full speed lifetime is rated at 50,000 hours (5.7 years). The fan includes a tachometer, allowing RPM to be mounted to detect obstruction of the fan.