GOYOJO GY1 Calibration Procedure

Calibration Procedure for Measuring Water Activity (aw)
Objective: To calibrate an instrument for measuring water activity (aw) using a
saturated salt solution.
Materials Required:
 Salt
(5 grams)
 Water (purified or distilled,
 Calibration container
Calibration Standard:
 Expected reading:
 Acceptable error range:
Steps:
1. Preparation of Saturated Salt Solution:
 Mix approximately 36 grams of salt with 100 ml of water to create a saturated
solution. Ensure salt particles are visible.
 Stir the mixture until it reaches a semi-melted state with visible salt particles. This
is the indication of a correct saturated salt solution.
 Seal the solution and let it rest for 1 day before use.
2. Sealing Calibration Measurement:
 Place the saturated salt solution in the calibration container.
 Seal the container with the instrument inside for a duration of 10-30 minutes.
 Note: It is acceptable if the instrument is turned off during this period. However,
do not separate the instrument from the container.
3. Reading and Interpretation:
 After the sealing period (10-30 minutes), turn on the instrument to obtain the
calibration reading.
 The calibrated value should read 0.75 aw, within an error range of ±0.02 aw.
Important Notes:
 Ensure the instrument remains sealed with the solution for the entire duration of
calibration, whether it is on or off.
 The calibration reading is most accurate if the container and instrument are not
disturbed during the sealing period.
 must adjust the values
10 grams)
0.75 aw
±0.02 aw