A humidity sensor of a sensing unit in a radiosonde of an aerological observation system has a dual cap that surrounds the humidity sensor. The dual cap includes an outer cap having a first ventilation hole formed on top thereof, a first air circulation door formed on the side periphery thereof to pass air therethrough, and a first wall formed on the side periphery thereof to close the flow of air. An inner cap is located inside the outer cap in such a manner as to be fixed to the outer cap and has a second air circulation door formed on the side periphery thereof to pass air therethrough. The second air circulation door faces the first wall of the outer cap.

A humidity sensor of a sensing unit in a radiosonde of an aerological observation system has a dual cap that surrounds the humidity sensor. The dual cap includes an outer cap having a first ventilation hole formed on top thereof, a first air circulation door formed on the side periphery thereof to pass air therethrough, and a first wall formed on the side periphery thereof to close the flow of air. An inner cap is located inside the outer cap in such a manner as to be fixed to the outer cap and has a second air circulation door formed on the side periphery thereof to pass air therethrough. The second air circulation door faces the first wall of the outer cap.

A wearable environmental sensor includes an environmental sensor arranged on a wall surface of a housing including a sealed section, the wall being in contact with an environment, and a protective structure formed around the environmental sensor, wherein the protective structure includes a plurality of ventilating holes, a sensor surface of the environmental sensor is arranged to face an opening of at least one of the ventilating holes, and an attaching part for attaching the environmental sensor to the wall surface comes into contact only with an edge of a sensor substrate of the environmental sensor and with a portion of a back face of the sensor substrate.

A wearable environmental sensor includes an environmental sensor arranged on a wall surface of a housing including a sealed section, the wall being in contact with an environment, and a protective structure formed around the environmental sensor, wherein the protective structure includes a plurality of ventilating holes, a sensor surface of the environmental sensor is arranged to face an opening of at least one of the ventilating holes, and an attaching part for attaching the environmental sensor to the wall surface comes into contact only with an edge of a sensor substrate of the environmental sensor and with a portion of a back face of the sensor substrate.