termohygrometer

A termohygrometer, sometimes called a thermo-hygrometer, is an instrument that simultaneously measures air temperature and relative humidity. It integrates a thermometer and a hygrometer in a single housing or relies on two sensors connected to a common processing unit. In modern devices, the temperature sensor is typically a thermistor, RTD, or thermocouple, while the humidity sensor is usually capacitive or resistive, based on a polymer dielectric whose electrical properties change with humidity. Some termohygrometers also compute derived values such as dew point, heat index, or absolute humidity from the measured temperature and relative humidity.

Types range from portable handheld units to fixed wall or ceiling-mounted devices, and many are part of larger weather stations or building automation systems. Digital models use microprocessors and display readings on screens or transmit data wirelessly for logging and remote monitoring.

Applications include meteorology and climate monitoring, indoor air quality control in homes and offices, HVAC system management, agriculture and horticulture, and preservation environments in museums or archives where stable humidity and temperature are important.

Calibration and accuracy vary by device. Factory calibration is common, with typical temperature accuracy around ±0.5–1.0 °C and relative humidity accuracy about ±3–5%, though higher-end instruments can offer better performance. Regular recalibration or cross-checks with reference standards or calibration salts may be recommended for precision work. Proper placement away from direct heat sources, drafts, or condensation is important for reliable readings.

See also: hygrometer, thermometer, dew point, weather station.