Food & proximate analysis
Water activity meter
Measures how much of the water in a food is free to support microbial growth and chemical change, as the ratio of the food's vapour pressure to that of pure water. Read on a scale from 0 to 1.
- Food & beverage
- Confectionery and bakery
- Meat and dairy
- Pet food
- Pharmaceutical
- Cosmetics
PREVENTIVE MAINTENANCE
Maintenance checklist
Daily / each use
- Verify with a salt standard
- Keep the chamber lid closed when not in use
- Check the chamber is clean and dry
Weekly
- Clean the chamber, mirror and sensor as the manual describes
- Check the lid seal
Monthly / quarterly
- Two-point or multi-point verification across the working range
- Check temperature reading against a calibrated thermometer
Annual
- Factory service and calibration if verification shows drift
- Replace capacitance sensor or filters as advised
SAFETY
Safety precautions
Before you work on the aw meter
- Most samples are low hazard, but handle food samples hygienically and dispose of them as food waste.
- Use the instrument's electrical supply and grounding as installed; do not open the case.
- Salt standards are mostly low hazard; lithium chloride solutions are irritant, so wear gloves.
In LimsPulse · Calibration Management
Keep every aw meter in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.