Rotronic HygroPalm AW1, Instruction Manual

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in_hypalm_aw1_v3.doc 

Operating Modes 

The HygroPalm AW1 has 3 operating modes:  

x

Standard Mode

: this mode is the default mode of the HygroPalm AW1. It is used for calibrating 

the probe above a reference humidity standard or to measure the full equilibration of a product 
(conventional water activity measurement). Both typically require from 30 to 60 minutes. 

In the standard mode, the HygroPalm AW1 displays the water activity and temperature measured 
by the probe. Trend indicators appear one minute after powering up the instrument (up or down 
arrow to the left of the water activity and temperature values). These indicators are used to detect 
equilibrium conditions as required during probe calibration. The probe is at equilibrium when both 
the up and down arrow are displayed at the same time. 

Upon powering the HygroPalm AW1, the instrument automatically defaults to the standard mode. 
If either the AwE or the AwQuick mode have been selected (see mode selection), the HygroPalm 
goes into the AwE or AwQuick mode as soon as the ENTER key is pressed. When neither the 
AwE mode nor the AwQuick mode are running, the HygroPalm AW1 returns temporarily to the 
standard mode. 

x

AwE mode

: this mode is essentially the same as the standard mode with the difference that the 

HygroPalm AW1 automatically detects equilibrium conditions and ends the measurement at that 
time by freezing the display. 

x

AwQuick mode

: this mode accelerates the water activity measurement and provides a result in 

typically 5 minutes. When temperature conditions are stable (both at the product and probe), the 
measurement obtained with the AwQuick mode is generally within ± 0.005 aw of the 
measurement that would be obtained by waiting for full equilibration of the product and probe. 

Mode Selection 

Note: upon being powered up, the HygroPalm AW1 remembers the last mode that was selected. 

The operating mode of the HygroPalm AW1 is selected from the Function Menu. To select any of 
the 3 modes, proceed as follows: 

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press the MENU key 

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use the UP or DOWN arrow to display MODE on the LC display 

-

press the ENTER key to select the MENU function 

-

use the UP or DOWN arrow to display the desired mode 

-

press the ENTER key to select the mode 

Depending on the mode that was selected, proceed as follows 

a)

Standard Mode: 

No further action is required after selecting this mode. Simply proceed with the measurements.