Vaisala HM45

Contact Instrument Solutions


The Vaisala HUMICAP hand-held humidity and temperature meter HM40 is available in four versions. You can choose either the standard or remote probe model according to your requirements along with a 4 mm diameter version and a long reach probe. Compact and easy to use, hand-held is an ideal spot-checking tool, at hand everywhere you go. It provides reliable measurement results in various environmental conditions from heavy industrial to clean, life science applications. The HM40's humidity measurement uses the same Vaisala HUMICAP sensor technology that landed on Mars aboard the Curiosity Rover, proving the sensor's excellence in terms of long-term stability and durability in demanding environments.


Models available are the HM41 (standard) fixed probe version, the HM42 4mm diameter probe version, the HM45 remote probe version and the HM46 unit with a 12mm diameter long reach probe.
  • Humidity measurement range 0 to 100 % rh
  • Operating temperature range - 10 °C to + 60 °C
  • Display a wide range of quantities RH, T, Td, Tw, a, x, h (absolute humidity, wet bulb temperature, enthalpy, mixing ratio)
  • Graph indicates when measurement has stabilized
  • Compact and robust housing
  • Large graphic display
  • Hold-button to freeze the screen
  • Interchangeable probes
  • Powered by standard AA batteries (2x)
  • Incorporates the proven Vaisala HUMICAP 180R sensor


Humidity measurement range 0 to 100 % rh

Humidity accuracy within the range 0 to 40 °C ± 1.5 % rh (0 to 90 % rh), ± 2.5 % rh (90 to100 % rh)

Temperature measurement range - 10 to + 60 °C

Temperature accuracy ± 0.2 °C

Power 2x AA size alkaline batteries, type IEC LR6

Support documents

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Vaisala HM40 user manual.pdf Vaisala HM40 user manual
Technical document
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Vaisala HM40 range data sheet.pdf Vaisala HM40 range data sheet
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