Vaisala HMP9 Humidity and Temperature Probe


The Vaisala HUMICAP® Humidity and Temperature Probe HMP9 is designed for easy installation in rapidly changing environments where a fast response time, measurement performance, and chemical tolerance are essential. The compact size enables installation even in tight spaces, with the probe head only 5 mm (0.2 in) in diameter.



  • Miniature probe head with low thermal mass for superior response time
  • RH accuracy up to 0.8 %RH
  •  Temperature accuracy up to 0.1 °C (0.18 °F)
  • Temperature measurement range −40 … +120 °C (−40 … +248 °F)
  • Sensor purge provides superior chemical resistance
  • Modbus RTU over RS-485
  • Compatible with Indigo transmitters and Insight PC software


  • Inlet monitoring in dryers
  • Air handling units
  • Data centers
  • Test chambers
  • Humidity measurement applications with temperatures under 120 °C (248 °F) that don’t involve high pressure


Vaisala Indigo family