The Water Activity, mainly reflects the amount of free water in the state of food balance, the stability of food and the possibility of microbial reproduction, and the chemical, enzyme and physical changes that can cause the change of food quality. It is often used to measure the dryness enduring ability of the microorganisms. 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, grain and fruits and vegetables can be judged. * This is a real portable water activity meter, with a weight of only 100 grams, lighter than a mobile phone, and a precision of 0.02 aw, easy to measure water activity. anytime and anywhere. * Sensors and readings are integrated. * Fast test, measurement of water activity in 5 minutes. * Easy reading, water activity and temperature of the samples displayed together. * It has automatic shutdown, manual shutdown function and under-voltage alarm indication function. * Use USB data output to connect with PC. * Provide Bluetooth data output choice.