LimsPulse
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
Illustration of Water activity meter
CALIBRATION

aw meter calibration procedures

Verification with salt standards

Reads salt solutions of known water activity and checks the meter reads each one within tolerance.

Open procedure
QUALIFICATION

Instrument qualification (DQ · IQ · OQ · PQ)

  1. 01

    DQ — Design qualification

    Defines the aw range, accuracy (for example ±0.003 for dew point instruments), temperature control and data needs.

  2. 02

    IQ — Installation qualification

    Records model, serial number, firmware, location away from draughts and direct heat, and power supply.

  3. 03

    OQ — Operational qualification

    Checks temperature control and aw accuracy with salt standards across the working range.

  4. 04

    PQ — Performance qualification

    Shows routine verification with standards and duplicate samples stays within the lab's acceptance limits.

In LimsPulse · Calibration Management

Keep every aw meter in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

See how