WS501 series Compact Weather Stations for measuring of air temperature, relative humidity, solar radiation, air pressure, wind direction and wind speed. Relative humidity is measured by means of a capacitive sensor element; a precision NTC measuring element is used to measure air temperature. The world renowned technology of Kipp+Zonen CMP3 is integrated. Ultrasonic sensor technology is used to take wind measurements. Measurement output can be accessed by the following protocolls: UMB-Binary, UMB-ASCII, SDI-12, MODBUS. One external temperature or rain sensor is connectable. The WS503 is a similar sensor available with a tiltable pyranometer for plane of array measurements of solar panels efficiency. Surface temperature and rainfall accessory sensors are also available as add on to the weather station.