Extech RH490 Precision Thermohygrometer

Amazon

Less than 30 second RH response time Water Vapour in GPP and g/kg Dual backlit display Simultaneous display of Humidity/Temperature, Humidity/Dew Point or Humidity/Wet Bulb Slim design with rubberized side grips, Weight: 0.440924524 Pounds, Manufacturer: FLIR Systems

Test-meter.co.uk

Precision thermohygrometer measuring humidity (0-100% RH) and temperature (-30°C to 100°C). Dual display shows RH, temp, dew point, wet bulb. Compact design with min/max recall. Includes case, battery, 1-year warranty.