||A series of weather transmitters measuring barometric air pressure, temperature, humidity, rainfall, wind speed and wind direction. The WXT530 series exceeds the IEC60945 maritime standard. Included in the series are the WXT531 (rainfall), WXT532 (wind speed and direction), WXT533 (rainfall, wind speed and direction), WXT534 (air pressure, temperature, humidity) WXT535 (air pressure, temperature, humidity, rainfall) and WXT536 (all parameters). Sensors included are the Vaisala WINDCAP ultrasonic wind sensor measuring horizontal wind speed accurate to the 3 percent at 10 m/s, and wind direction to an accuracy of 3 degrees. Barometric pressure, temperature, and humidity measurements are combined in the PTU module using capacitive measurement for each parameter. Rainfall parameters are determined using the Vaisala RAINCAP sensor, measuring to an accuracy of 5 percent.