Schaller humimeter RH2 – Precision Water Activity (aw) Meter for Laboratory and Food Applications

Water activity indicates the amount of unbound water (free water) in a material. It is an important factor in food preservation and quality control - for example for the shelf life of meat or other foods. 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 food moisture content meter allows quick and easy measurement of water activity. We offer two different sensors:

• In the measuring chamber Due to the large sample volume, larger quantities can be measured within a short time. This enables a higher number of random samples to be drawn.
• The measuring cell is used for very small sample amounts. In addition, the sensor can be replaced here.
• Many products can be measured, such as butter, fruit mixtures, spices, granules, PVC, mushrooms, xylitol or seasoning.

With our aw value measuring instruments for food, the shelf life and quality can be secured and controlled.

The measuring device is a laboratory device and enables measurements in accordance with EN ISO 21807.

In the download area you will find the instructions for calibration and adjusting the water activity meter humimeter RH2.

Benefits

• 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
• portable handset
• High measuring accuracy

Handling and measurement process

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).

Technical information