Step 1

After Login in the HygroLab select in the "Main menu" > "Measurement" to get an overview of all current measuring.

In this menu it shows all important information of the current measuring (Sensor, Temperature, relative Humidity (RH) and water activity (AW)).

In the overview it's possible to "start all available measurements" which are connected to the HygroLab. Contrariwise it's also possible to "stop all running measurements" at once.

The lower menu is always in place and represents the each sensor ports (1 to 4 from left to right).

Each connected sensor has 3 different options to select.

Select "Measurement Data" to go in the measurement submenu to select the right measuring option.

NOTE: By adding a new measuring the old measuring are deleted only in the current measurement data, the report of the old measurement is always saved as a document in the measurement documents.

Step 2

After selecting in the lower menu the required probe the option "Measuring Data" a submenu will open up.

This submenu is build up with two sides. The left side shows always the measuring information and the right is configurable with options on the right side of the screen.

NOTE: Trend indicators While measuring the HygroLab always shows with arrows the trend for the temperature, the humidity and the water activity. The trend indicators are yellow and green arrows.

In the measuring submenu there are 5 different options to choose.

The most important option for the measuring is the "Measurement method", there you can not only choose the measuring method also the set up for the measurement.

Step 3

After selecting the option "Measurement method" there are 2 different method which can be chosen to measure water activity. The "AWE" mode is the exactest measure method and the "AW Quick" mode is the fastest method.

AWE mode:

The HygroLab waits for the full equilibration of the measured product and probe. For most products, this takes from 30 to 60 minutes. The HygroLab automatically detects equilibrium conditions (humidity and temperature) and ends the measurement at that time by showing in the measuring data a green OK. The HygroLab displays a trend indicator to the left of the temperature and the aw value.

AWE Quick mode:

The HygroLab uses an algorithm to accelerate the water activity measurement and provides a result in typically 5 minutes. The measurement ends automatically and it shows then a green OK in the measuring data. When temperature conditions are stable (both at the product and probe), the value measured with the AWE Quick mode is generally within ± 0.005 Aw of the value that would be obtained by waiting for full equilibration of the product and probe.

Using the AWE mode

Go into the measurement method and select the AWE. Then specify the tolerance of the equilibration (temperature and water activity) with the Stab.T and the Stab.AW parameters. When all these parameters are fulfilled the measurement will end.                                

•Define the stability of the temperature per minute

Stab.T: 0.1 (°C / °F) [/min] → Our recommendation

•Define the stability of the water activity per minute

Stab.AW: 0.0001 [/min] → Our recommendation

NOTE: Lower numbers for the Stab.T and the Stab.AW ensure more accurate results but causes measurements to take longer.

Since version 3.0.0.0 and higher, it is also possible to display additional parameters, such as the dew point. This parameter is selected for the 1. Unit and 2. Unit and is then displayed graphically during the measurement. However, for the stability of the temperature (Stab.T) and AW (Stab.AW), the temperature and AW are always taken as parameters regardless of which of the two units was selected for the AWE measurement.

The 1. Unit only has an influence on the Setpoint, if another parameter is selected, the Setpoint parameter will be changed.

Using the AW Quick mode

To use the AW Quick mode the procedure is almost the same as the for the AWE mode. There is no setting of Stab.AW (stability of the water activity) instead there is Dwell time. The value of the Dwell time can be set by the user and is a tradeoff between speed of measurement and accuracy. We recommend for the Dwell time of 3-4 minutes and a Stab.T of 0.1 (°C / °F) [/min]. Generally, a longer Dwell time produces more accurate results but causes measurements to take longer. The Dwell time also strongly depends on the sample which releases moisture in the environment faster or slower. The user needs to adjust for example a higher dwell time in case of a sample with a slower release of moisture.

NOTE: After changing the settings select "Save" to adopt the new settings.

Since version 3.0.0.0 and higher, it is also possible to display additional parameters, such as the dew point.

However, for the stability of the temperature (Stab.T) and Dwell time, the temperature and dwell time are always taken as parameters regardless of which of the two units was selected for the AWQ measurement.

The 1. Unit only has an influence on the Setpoint, if another parameter is selected, the Setpoint parameter will be changed.

Recommended values overview:

Please note that this recommended values only applies for measurement in stable and air-conditioned rooms resp. laboratories (at 23°C ±5°C).

NOTE: During the measurement the climate condition needs to be stable. Unstable condition makes the measurement unnecessary longer (mostly for the AW Quick function) and inaccurate.

See more information here: HC2A-AW / HC2A-AW-USB