Model 8339 Laser Ceilometer simultaneously detects and measures up to 4 layers of clouds at heights up to 30,000 ft. Measures the thickness of individual cloud layers. Penetrates clouds using an eye-safe, low-power, laser transmitter. Advanced digital signal processing algorithms provide accurate reporting of cloud base locations in all weather conditions. Provides accurate data in a variety of challenging weather conditions, whether heavy recipitation or low clouds. Both vertical visibility and ground-based obscurations can be reported while locating higher layers of clouds.