Portable Instrument for determination of water activity (aw value) of food with data log functions. Suitable for measuring material like butter, fruit mix, spices, mushrooms, flour, biscuits sausages and many more. UKAS calibration included.
If you require PC connectivity, data transfer, and advanced analytics, consider the Water Activity Meter Kit with USB Data Interface and Log Memorizer Software (VWAM-12). For pricing details on the VWAM-12, please contact our sales or customer service team.
Water activity is a key factor affecting the stability of powders and dehydrated products during storage. By controlling water activity, manufacturers can maintain product structure, texture, stability, density, and rehydration properties.
Water activity also indicates how the water in food interacts with microorganisms. Higher aw values promote faster growth of bacteria, yeast, and mould. Below a certain threshold, only non-harmful microorganisms can grow. Lower the aw even further, and few - if any - microorganisms can grow and spoil the food.
Water activity influences the following characteristics:
- Microbiological stability
- Chemical stability
- Enzymatic stability
- Colour, taste, and nutritional value
- Content of proteins and vitamins
- Stability of composition
- Shelf life
- Storage and packaging
The VWAM-01 Water Activity Meter enables the quick and easy determination of water activity (aw value). Thanks to the large sample volume of its measuring chamber, higher quantities can be tested within a short period of time - allowing for a greater number of random samples to be taken efficiently. Please note: this instrument is not suitable for juices (syrup), acidic foods such as vinegar, or food and beverages containing alcohol.
Kit Components
- Humimeter Water Activity Meter with case and rubber protection
- Water activity measuring chamber with moisture and temperature sensor (2m cable)
- 2 screw glasses (186 ml)
- 2 screw glasses (245 ml)
- 4 twist-off caps
- Certified calibration ampoules
- Factory calibration certificate
Key Features
- Measure relative humidity, absolute humidity, dew point, equilibrium moisture content, aw value.
- Long, stable humidity sensor.
- Online function, Hold function, manual data memory.
- Automatic datalog for up to 10,000 logs with measuring point report.
- User-programmable characteristic curves for calculation of equilibrium moisture content.
- Analysis on PC and printer available.
- Optimal documentation of your quality.
- Rapid conditioning due to integrated fan regulating the air circulation.
Water Activity and Micro-organisms
Water activity reveals the amount of water available to microorganisms. Each type of microorganism requires a minimum water activity value in order to grow. Below are some examples of typical values taken from literature:
| Measuring range | 0.03 to 0.98 aw | Resolution | 0.001 aw |
|---|---|---|---|
| Calibration | 0.10 to 0.80 +/- 0.01 aw, 0.00 to 0.10 and 0.80 to 0.98 +/- 0.04 aw (at 25°C) | Temperature range | 0 to + 50°C, calibration +/- 0.5°C (at 25°C) |
| Measuring range of relative humidity | 0 to 100% rh, resolution: 0.1% rh | Temperature | Can be set to °C or °F as required |
| Dew point | -55°C to + 60°C, resolution 0.1°C, -67°F to 140°F | Absolute humidity | 0 to 130 g/m³, resolution 0.1 g/m³ |
| Equilibrium moisture content | 2% to 30%, resolution 0.1% |