Improvements in AMPS Relative Humidity Processing

AMPS (Automated Meteorological Profiling System) balloon-borne radiosondes measure winds, temperature, and humidity at launch ranges. Sippican is introducing a new humidity sensing element and algorithm for its AMPS radiosondes. A new capacitive sensor technology, replacing the resistive hygristor element, has improved accuracy throughout the temperature and humidity range. Worst case absolute errors are approximately ±5% RH. The new sensor also extends the temperature range by 15°C, providing reliable measured data at temperatures down to approximately -55°C. Processing employs a simplified objective algorithm across all conditions. Sensor uniformity obviates any need for lot-specific adjustment coefficients for humidity or temperature extremes.