How to measure water activity with the Rotronic HP23-AW HygroPalm Psychrometer

Measuring water activity with the HP23-AW Psychrometer from Rotronic is a breeze!

To begin your measurement ensure both samples need to be at similar ambient temperature so the readings are as accurate as possible and that you're using the right cup sizes for your samples.

Switch easily between both samples' measurements via the probes by pressing the up and down arrows on the psychrometer. Using the HP23-AW for AW measurements starts both probes at the time so you don't have to spend time getting the other probe set up and wait for the second reading to be complete.

How to calibrate the Rotronic HP23-AW HygroPalm Psychrometer

Is it time for a calibration? We'll walk you through how to do it yourself in this video.

Each calibration kit comes with calibration solutions which come in 5 single-use, glass vials and a detailed calibration certificate. Standard calibration points for the AW probe are 0, 10, 35, 80 and 95% RH.

Step one: Collect all of the as found calibration points and save each test point.
Step two: Apply the calibration points if desired.

It's important to note that the instrument and standards are at the same ambient temperature (avoid direct sunlight and ventilation vents) so the calibration is completed with the utmost accuracy.