Rapid measurement of water vapour pressure at the saturation point using anew hybrid humidity sensor

A new hybrid humidity sensor comprising a conventional capacitance humidity sensor and a planar heating element is described. Owing to its short respo nse time of only a few milliseconds, its great measuring accuracy, large me asuring range, and simplicity in handling, the sensor is suitable for measu ring water vapour partial pressure in gases with rapidly changing flow and direction, e.g. in ventilated patients in the fields of anaesthesia and int ensive care medicine. The small dimensions permit measurements at almost an y location within the ventilation system.