Using thin-film sensor, whose capacitance varies proportionally to medium relative humidity, RHA measures relative humidity of air and non-aggressive gases at normal ambient pressure and converts it into standard voltage signal. Based on the RHT transducer, but with its electronics fitted into a cylindrical body, this probe is especially suitable for fast measurements in combination with handheld humidity measuring devices that feature programmable or scalable input. Furthermore, a platinum temperature sensor may be built in the probe for simultaneous medium temperature measurement. Through its flexible cable with miniature connector, the RHA probe can be easily connected to a H5800 meter to form a lightweight multifunctional and widely applicable device for handheld relative humidity measurement