Portable Water Activity Meter (WA-60A)

The AMTAST WA-60A measures water activity (aw) and sample temperature in a handheld unit weighing just 100 g, for checks in the warehouse, on the production floor or in the field without taking samples to the lab.

Why it is measured

Water activity is not the same as moisture content: it shows how much water is available for microbial growth, chemical reactions or caking. That is why it governs the stability and shelf life of dried and intermediate-moisture foods, powders and raw materials.

Where it is used

• incoming inspection of powders, granules and dried foods
• routine checks on the plant floor and in the warehouse
• dried fruit, dried meat, nuts and other intermediate-moisture products
• pharmaceutical and nutraceutical raw-material screening

Key specifications

• Range 0 to 1.0 aw, 0.01 aw resolution, ±0.02 aw accuracy
• Measurement time about 5 minutes
• Backlit LCD showing aw and temperature together
• Non-conductive humidity sensor built into the body
• Two AAA batteries, with auto-off and low-battery alarm
• USB output to PC; Bluetooth optional
• Operates at 0 to 50 °C and below 95 % RH
• 135 × 70 × 44 mm, 100 g without batteries

Versions

• WA-60A: standard unit
• WA-60AS: with software and cable
• WA-60AB: with Bluetooth and software

Practical note

Let the sample and the meter reach the same temperature before measuring; a temperature difference between them is the most common cause of erratic aw readings.