Home » Freund


A leading manufacturer of pharmaceutical and food additive formulation devices

Water Activity Meter EZ-200

Features a colour touch panel and is accurate,  easy to use, and simple to maintain.

Water activity (Aw) is related to quality in food, pharmaceutical, and various other fields.
Freund has developed and distributed equipment to measure Aw together with quality preservation agents for many years.
For highly accurate short-time measurements, use the "EZ-200" that can be easily operated by anyone for quality management.

  • Features a colour touch panel that provides intuitive controls.
  • Allows for wide-ranging measurements between Aw 0.10 to 0.98 to be performed in just 10 minutes, a reduction in time of 30% compared to previous models.
  • Allows for accurate measurements regardless of whether the sample is a solid, liquid, or powder.


Quality Control | Water Activity | HACCP

  • Wide-range measurement with a high degree of accuracy
  • Short-time measurement (30% shorter than conventional products)
  • Accurate measurement of Aw with a sensor that is not easily affected by Ethanol
  • Equipped with a colour touch panel for superior operability. Various settings can be made.
  • Customer-replacement/calibration of the sensor (tool-free)
  • Suppresses sensor deterioration by acids, etc., by attaching a sensor protective filter (optional).
  • Saves up to 100 events of data on the main body; USB flash memory available (CSV output)

What is Water Activity (Aw)?

Water activity is a comparison between the surface moisture vapor pressure of a food item (P) and the vapor pressure (P0) of pure water (water activity AW = P/P0: value 0 to 1). This is the same value as if the food item was placed in a sealed container the equilibrium relative humidity percentage of the inside of the container (which equals Aw x 100) was divided by 100. In addition to the water content (percentage of water content) as the physical property value of the food item, water activity is used in fields such as product design, quality control, and HACCP.

The water contained in food items does not always exist as pure water, some of it is a salt or sugar solution, or a protein hydrate. Water activity reflects the state of highly mobile free water within the food item, allowing for the existence of microorganism growth to be confirmed. It also provides clarity regarding the relationship between the state of free water and the speed of microorganism growth.

Lowest levels of water activity required for microorganism growth

Mold: 0.80(0.65)

Yeast: 0.88(0.65)

Bacteria: 0.91(0.75)

*The values within brackets are for halophilic, glucose tolerant, and xerophilic varieties.

Water activity tends to increase as water content rises, but it is not a uniform correlation.

Contained water


Free water


For example, jam has a high moisture  content but the water activity is not so  high because most the moisture is  combined with the sugar. On the other hand, white bread does not use a lot of sugar or  salt so the value of water activity  increases considerably to around 0.96.