Menetelmä suhteellisen kosteuden mittaamiseksi, etenkin radiosondeissa sekä menetelmää soveltava kosteusanturi

摘要

Method and sensor for measurement of relative humidity by using a capacitive moisture sensor 10 or combination 101, 102; 10P of sensors, especially in radiosondes. A substance 12 is used in the sensor between capacitor plates whose permittivity is a function of the amount of water absorbed by the substance 12 in question. In the method the cited sensor 10 or combination is heated to reduce harmful effects caused by ice, frost or condensed moisture that has collected on the surface of the sensor and/or in the ceramics. The sensor capacitance CM or a part of it C1.CN is heated in an up-to-date method and/or locally periodically with electric current I and observation of the sensor capacitance CM is carried out without measurement of the sensor's temperature when the sensor capacitance or a part of it C1.CN is significantly cooled by the surrounding temperature. Two 101, 102 or several different sensors are used in the method or a parallel connection of several partial sensors C1.CN or the like. During use of several different sensors 101, 102, each of the sensors is heated in turn and the relative humidity is observed primarily from the cited heating based on sensors 101, 102 or partial sensors C1.CN which are cooled sufficiently. In addition, a system is presented for measurement of the relative humidity in which the method and/or sensors are applied.