trockenthermometer

Trockenthermometer, commonly called a dry-bulb thermometer, is an instrument used to measure the temperature of the surrounding air. It consists of a sensing element that is exposed to the air and kept dry during measurement, so the reading reflects the ambient air temperature rather than any temperature of moisture on the sensor.

Measurement is typically performed in a radiation-shielded exposure, such as a Stevenson screen, to minimize heating from direct sunlight and radiative heat from nearby surfaces. In meteorology and climatology, the dry-bulb temperature is used together with a wet-bulb thermometer to derive humidity-related quantities such as relative humidity and dew point through psychrometric methods.

Construction can be traditional or modern. Historically, dry-bulb thermometers used mercury or spirit in a glass enclosure, but many contemporary devices use electronic sensors such as thermistors or RTDs with a protective casing. Digital implementations can log data and connect to weather stations or building automation systems, offering continuous ambient temperature monitoring.

Calibration and maintenance are important for accuracy. The device should be calibrated against known temperature references and kept out of direct sun, precipitation, and strong drafts when not in use. Regular cleaning, inspection of the sensing element, and replacement of aging components help ensure reliable readings.

In addition to meteorology, dry-bulb sensors are widely employed in HVAC, industrial process monitoring, and research to monitor ambient conditions and control equipment. The dry-bulb reading serves as a fundamental baseline for environmental measurements and is a standard component of meteorological observations and related fields.