E-M-AwTherm-V1.1
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
AwTherm: Water Activity at Controlled Temperature
Instruction Manual for Software
Version 1.1
Document Type
Page
14
Document title
Figure 3-13 Define new Set Point Temperature
AwTherm will now control the temperature of the chamber to the new temperature. The time it
takes for the chamber to reach the temperature will depend on the ambient conditions, and the
initial and set point temperatures. Depending on the magnitude of the temperature change
required, the instrument will slightly overshoot, before coming back and stabilising. The Trend
Indicator (19) will show whether the unit is heating or cooling. When stable (to within the defined
AwE/AwQ temperature tolerance – see Section 3.3) the Trend Indicator will display up and down
indicators simultaneously.
Note that the chamber will reach a stable set point temperature before the sample, depending on
the initial temperature of the sample. See Sample Preparation: best practices and operational
considerations (Section 4.3) below for further details and advice.
3.3
Making Measurements
AwTherm features two modes for measuring water activity.
●
AwE mode:
In this mode AwTherm monitors the stability of both temperature and humidity. The
measurement is automatically ended as soon as both humidity and temperature reach
equilibrium. The natural (or static) equilibration of most products typically requires from 15 to 60
minutes and can take as long as a couple of hours.
© 2012; Rotronic AG
E-M-AwTherm v1.1
