Rotronic HygroPalm AW1, Instruction Manual

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in_hypalm_aw1_v3.doc 

Prior to using the Adjust M.PT function, monitor the water activity and temperature readings in the 
Standard Mode. Wait for the trend indicators to show stable conditions both for water activity and 
temperature. When the probe is at equilibrium, activate the Adjust M.PT function and make the 
appropriate selections: 

a)

RHS

: press the ENTER key to select this item. The LC display shows the value read by 

the probe at the time the ENTER key was pressed. The letters “RHS” are displayed on 
the message line. Use the UP or the DOWN key to change the humidity value to match 
the mean value (at 23

q

C) written on the certificate supplied with the standard. For a faster 

change, keep the key pressed down. Press the ENTER key when done. 

Note: in the RHS mode, the software automatically compensates for the effect of 
temperature on the humidity standard. No additional correction is required. 

b)

Humidity or Temperature

: press the ENTER key to select. The LC display shows the 

value read by the probe at the time the ENTER key was pressed. The word “humidity” or 
“Temperature” is shown on the message line. Use the UP or the DOWN key to change 
the humidity or temperature value to match the value of the reference environment. For a 
faster change, keep the key pressed down. Press the ENTER key when done. 

After pressing the ENTER key, the message “sure?” should appear on the LC display. Press 
ENTER to confirm. Next, the LC display will confirm that the probe adjustment has been 
successfully completed. At that time, press ENTER to exit or MENU to return to the function 
Adjust M.PT and do another calibration point.

Carry on in the same manner for each calibration point, following the sequence described above. 

Note: you can exit the function at any time (without calibrating the probe) by pressing the MENU 
key. 

ADJUST 1PT (1-point adjustment against a reference) 

Definition

The Adjust 1PT function permits to do a 1-point adjustment (temperature or humidity) of the  
ROTRONIC HygroClip digital probe against a known reference environment. This function is 
limited to a simple offset adjustment that is applied across the entire measuring range.  

Notes:

Water activity calibration is actually a calibration of the relative humidity signal provided by the 
probe. The parameter used is relative humidity which is equal to 100 x aw. 
For example, 1.00 aw = 100 %RH. 

A 1-point adjustment is no substitute for a full calibration (2 or more points). Doing a 1-point 
adjustment can improve accuracy over a narrow range of conditions and may also be detrimental 
to accuracy at other conditions.