Features:

§  Highly precise with 0.03 aw accuracy

§  Ultra-portable with a weight of only 100g, for on-site measurements and easy carriage

§  Simultaneous display of water activity and temperature

§  Data logging

Applications:

Water activity affects the shelf life, safety, texture, flavor, smell and stability of food. This measures the dryness enduring ability of the microorganisms in food samples. By measuring the water activity of food and selecting reasonable packing and storage methods, the use of preservatives can be reduced, and the shelf life of food, grains, fruits and vegetables can be judged. Widely useful in food, pharmaceutical, cosmetics, seed storage, tobacco industry, etc.    

Measuring Principle:

What is water activity? It is the amount of free water in the state of food balance. With the possibility of microbial reproduction, chemical, enzyme and physical changes in food over time, it can cause change of food quality, and consequently its shelf life.

This meter measures the water activity by measuring the relative humidity or vapor pressure of the water molecules in the food sample. The principle behind this is that the amount of water a substance adsorbs is proportional to the vapor pressure at a given temperature. The sample is placed in a closed chamber for some time, and the water activity is displayed in ‘aw’ units. Higher ‘aw’ unit mean more free water biologically available for micro-organisms to grow.