Whirling Hygrometer

A Whirling Hygrometer, also known as a Sling Psychrometer, is a portable instrument used to measure relative humidity by comparing the readings of a dry bulb thermometer and a wet bulb thermometer while the instrument is rotated through the air.

Mercury-filled thermometers provide stable, precise, and repeatable temperature measurements over a wide range. However, due to environmental and safety regulations, mercury instruments may be restricted or prohibited in some countries. Always follow local regulations regarding their use, handling, and disposal.

The continuous airflow created by whirling the instrument improves evaporation from the wet bulb, resulting in more accurate humidity measurements than a stationary wet and dry bulb thermometer.

High-quality mercury-filled models typically provide temperature accuracy of approximately ±0.5°C to ±1°C, depending on calibration and operating conditions.

No. Relative humidity is calculated using the wet bulb and dry bulb temperature readings with the help of a psychrometric chart, humidity table, or calculator.

Replace the wick whenever it becomes dirty, worn, or loses its ability to remain properly saturated.

A Whirling Hygrometer is an excellent choice for reliable field humidity measurements because it is portable, does not require electrical power, provides dependable results when used correctly, and is well suited for environmental, educational, and industrial applications.