Whether you want single readings or the continuous monitoring of relative and absolute humidity, this multisensor can do the job. It also reports temperature, from which the device calculates dew point (based on the humidity and temperature measurements).
Specifications:
Humidity: Range, 0 to 100% RH and 0 to 50 g/m³ AH; Accuracy, ±2% RH and 10% of reading AH
Temperature: Range, –20 to +55° C; Accuracy, ±0.5° C
Dew Point: Range, –50 to +55° C; Accuracy, ±2° C
Conduct weather station experiments.
Check the humidity in a terrarium, greenhouse, or other enclosure.