Water Activity Meter EZ-200 Water Activity Meter EZ-200 Water Activity Meter EZ-200
Water Activity Meter EZ-200

Water Activity Meter EZ-200 Water Activity Meter EZ-200

The EZ-200 is our latest water activity meter.
It features a color touch panel and is accurate,
easy to use, and simple to maintain.


Excellent User

Features a color 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.

Excellent User Friendliness Excellent User Friendliness Excellent User Friendliness


Features sensors that can be exchanged and calibrated by the customer. Maintenance can be performed without the use of tools. Specialized repairs are not required when the sensors become degraded. Reagents can be reused, allowing for cost reductions when performing periodic tests.



Features accurate Aw-measuring sensors with low-susceptibility to the effects of alcohol.
Using the optional sensor protection filter will reduce sensor degradation due to acids etc., ensuring that they can continue to be used for a long period of time.


with USB

More than 100 pieces of data can be stored on the meter. It can also export records to USB memory drives (in CSV format).

Made in Japan

The EZ-200 is the result of our accumulated know-how
and development ability.

FREUND developed the first Japanese-produced electric resistance water activity meter in 1983 and is now a leading company in the field. We have now sold more than 1000 units worldwide.

Product Specifications

Product Name
Water Activity Meter
Electric resistance type
Measurement range
Measurement accuracy
±0.01 Aw(25℃±0.3℃)
Measurement Time
On average 10 minutes / sample*2
4 points (0.33、0.53、0.75、0.93 Aw) / 25℃
AC adapter
Input:100-240V 50-60Hz
Main unit rating
DC24V 0.65A
Power adapter, sample containers(5), reagent of saturated salt solution for calibration(4 types)*3,
silica gel*4, grease, dispensing spoon, pipette

*1:When the third decimal point is "rounded." *2:When the sensor protection filter is not attached *3, *4:With matching container
If any reagent of saturated salt solution for calibration finished up,purchase the guaranteed Reagent.

Optional accessories

Sample container
10 units
Sensor protection filter
10 sheets
Inlet air filter
2 units
Replacement packing
2 units
50 g
sensor board
1 set

(with packing, grease and saturated salt solution for calibration)

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. This product uses electric resistance sensors that are based on official methods provided by the Ministry of Health, Labour and Welfare.

Contained water

Contained water

Free 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.

Free water
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