[. . . ] www. vaisala. com Vaisala Visibility Sensor PWD50 Dependable operation of automated observation networks is a must today. [. . . ] The PWD50 can also be upgraded with present weather sensing capabilities to PWD52. The upgrade enables a wide range of valuable outputs including present weather, precipitation type, precipitation rate and accumulation. These complement the versatile use of the sensor. Robust and Dependable The downward-facing sensor hoods protect the optical surfaces from contamination, resulting in low maintenance needs and costs. The optional hood heaters prevent the buildup of ice and/or snow in the optical path. Solid Track Record Thousands of PWD series sensors have been installed all around the world. They have proved their robustness in the harshest climates and most demanding conditions, ranging from offshore to desert and from airport to roadside. PWD50 reports reliably meteorological visibility from 10 meters to 35 kilometers. Technical Data Visibility measurement Operating principle Measurement range (MOR) Accuracy Forward scatter measurement 10 . . . 35 km Dimensions 69. 5 cm (27. 36") 19. 9 cm (7. 83") 15 cm (5. 91") Electrical Power supply Power consumption Options luminance sensor hood heaters Outputs 12 - 50 VDC (electronics) 24 VAC or 24 VDC for hood heater option 3W . 2 W (24 V) 65 W (24 V) RS-232 or RS-485 (2-wire) Three programmable relay controls (open collector), visibility alarm thresholds and delays configurable, fault alarm relay 0 . . . 20 mA analog current 4 cm (1. 57") Mechanical Dimensions Weight 199 mm (h) x 695 mm (w) x 404 mm (d) (7. 83" (h) x 27. 36 " (w) x 15. 91"(d)) 3 kg (6. 61 lb. ) Accessories/options Interface unit with power supplies Pole mast Hood heaters for winter conditions Support arm for mast installations Pole clamp kit for mast top installations Luminance sensor PWL111 Calibration set PWA12 Maintenance cable 16385ZZ 115/230VAC Environmental Operating temperature Operating humidity Protection class -40 . . . [. . . ] All specifications -- technical included -- are subject to change without notice. 40. 4 cm (15. 91") [. . . ]