Instruction Manual
IN-E-HyLab-V4_11 
Rotronic AG 
Bassersdorf, Switzerland 
Document code  Unit 
Instruction Manual
Document Type 
HygroLab bench top indicator version 4: 
instruction manual 
Document title 
Page  25 of 51 
© 2006; Rotronic AG  IN-E-HyLab-V4_11 
6.7  PROBE 
Definition 
This function displays the version number and serial number of any ROTRONIC HygroClip digital 
probe connected to the instrument. 
Procedure 
Prior to entering the function, select the probe to be displayed (this is the same as the probe that 
was last displayed). 
When entering the function, the version number of the probe is displayed first. Use the ▼ or ▲ key 
to display the serial number of the probe. 
6.8  SETTINGS 
Definition 
This function is used to do the following: 
• Turn the trend indicators on or off 
• change the symbol used for relative humidity or display humidity as Water Activity (aw) 
• adjust the fixed value of barometric pressure used in some psychrometric computations 
 (except HygroLab 1) 
• select between the Metric or English unit system 
Procedure 
Trend: use the ▼ or ▲ key to enable or disable the trend indicators. 
The trend of humidity and temperature is shown on the display by an arrow (up or down) to the left 
of the measured value. Both arrows are shown to indicate stable conditions. Stable conditions are 
defined as rate of change of less than 0.02 %RH / min or °C / min. 
Signal stability is first evaluated after 60 seconds into the measurement and is updated every 30 
seconds. 
Note: when the trend indicator is enabled, the symbol for the calculated parameter (e.g. Dp for dew 
point) is no longer displayed to the left of the numerical value. 
Humi Unit: use the ▼ or ▲ key to change the symbol used for relative humidity (depends on 
country and language) or to display humidity as water activity. 
Press. Const. (except HygroLab 1) : use the DOWN arrow key to select the digit to be changed. 
Use the UP arrow key to change the value of the digit. 
Units: use the ▼ or ▲ arrow key to toggle between Metric and English. 










