Climate precision moisture analyzer with data logger for laboratory, climate and environmental applications as well as aw value measurements.

The simple handling guarantees a cost-saving and error-free measurement of the activity of the water value of food. Simply fill the material into the aw value chamber and close it.

After an appropriate conditioning time (time period until a constant climate in the chamber is reached = moisture equilibrium) the water activity can directly be read off the display of the humimeter RH2 water activity meter.

The time it takes to reach moisture equilibrium depends heavily on the material to be measured and the temperature. Hygroscopic materials such as cornflakes assimilate in a much shorter time than whole corn kernels. In this context, it is important that the samples have the same temperature as the measuring device or the measuring chamber - high temperature differences lead to a longer conditioning time. This material-dependent conditioning time is a physical phenomenon and cannot be shortened artificially. Generally, the conditioning time is from 5 minutes to about an hour.

The moisture equilibrium is achieved when the displayed measuring value is no longer changing for a period of several minutes (e.g. 10 minutes, changes less than 0,002 aw).

  • Aw value measuring range from 0,03 to 0,99 aw
  • Resolution 0,001 aw
  • Calibration 0,10 to 0,80 +/- 0,01 aw
  • Long-term stable sensor technology
  • Very quick adjustment process
  • Lifetime Support


Precise climate moisture analyser and thermo-hygrometer with data logger, appli- cable for measuring air humidity and temperature, synthetic granules and special material, for laboratory, climate and environment applications and aw-value meas- urements.


The water activity of food indicates the amount of unbound water in a material. This quality factor, also known as the aw value, depends on the water vapor pressure in the material, the current temperature and the water vapor pressure in the environment.

The Humimeter RH2 Water activity meter allows quick and easy determination of water activity. In addition, due to the large sample volume of the water activity measuring chamber, larger quantities can be measured within a short time. This enables a higher number of random samples to be drawn.

Measurable special materials include butter, fruit mixtures, spices, granules, PVC, mushrooms, xylitol or even seasoning.


  • Aw value, relative humidity, absolute humidity, dew point, equilibrium moisture content
  • Fast adjustment behavior
  • Long-term stable humidity and temperature sensors
  • Easy data storage on the portable moisture meter
  • Optimal documentation of your quality

Scope of delivery

Humimeter RH2 with rubber protection cover and batteries

Required accessories

 Separate sensor

Humimeter - Technical data
Automatic datalog Datalog for 10.000 values with measuring point report
Aw value 0,0 to 1,0, resolution 0,001
Equilibrium moisture content granules Resolution 0,01%
Equilibrium wood moisture content 2 to 30%, resolution 0,1%
Temperature Measuring range see sensor, resolution 0,1 °C
Relative humidity Measuring range see sensor, resolution 0,1% RH
Dew point -55 to +60°C, -67 to 140°F
Memory function Online function, hold function, manual datalog
Absolute humidity 0 to 130 g/m³, resolution 0,1 g/m³
Dimensions 145 x 75 x 30 mm
Weight 210 g (including batteries)
Power Supply 4 x 1,5 Volt AA Alkaline batteries
Menu languages English, German, Italian, French, Spanish, Portuguese, Czech, Polish, Russian

Humimeter RH2 water activity meter

  • Brand: Schaller
  • Product Code: 12005 aw
  • Availability: 10-15 Days