scigiene AW1 User manual

1
User Manual
Humimeter AW1 Meter
2018

2
User manual - Definitions
Water Activity: Water activity or aw is the partial vapor pressure of water in a
substance divided by the standard state partial vapor pressure of water. In
simplified terms, aw is the measure of “free” water in food or other product of
interest that is available to support the growth of microorganisms including
spoilage organisms.
Relative air humidity: indicates the relation between the current water
vapour pressure and the maximal possible water vapour pressure (called
saturation vapour pressure).
The relative humidity shows the degree to which air is saturated with water
vapour. For example:
50% relative humidity indicates that at the current temperature and the current
pressure the air is saturated with water vapour for half of its value, 100 %
relative humidity means that the air is totally saturated. When the air has more
than 100 % of relative humidity, the excessive moisture would condense or
form fog.
Absolute humidity: shows the contained amount of water in grams per cubic
metre of air. The absolute humidity is a direct degree for the amount of water
vapour contained in a certain air volume. It shows how much moisture can
maximally condense or how much water has to be evaporated to receive a
certain desired air humidity.
Dew point temperature: The dew point indicates the temperature that the not
completely saturated air has to reach in order to be completely saturated with
water vapour. If the room with the current relative humidity is cooled down to
the dew point temperature, the water vapour begins to condense.
Empty calibration curves: There are another 10 empty calibration curves
stored in the measurement device. These can be used for special fruits or
variety calibration.

3
Detailed definition of Water Activity:
Water activity or awis the relationship between the partial water vapour pressure in food (p)
and the saturation vapour pressure of pure water (p0). It is an important indicator for
product quality in the food, tobacco and pharmaceutical industry and is indicated in an aw
value from 0…1.
Water activity is synonymous with the equilibrium moisture content –the relative humidity
of air in equilibrium with the sample product.
The relative humidity of air however is indicated in %.
Water activity value is temperature dependent. For the determination of water activity at a
desired temperature, the measuring device and the product sample should be stored at the
same temperature before starting the measurement.
The humimeter AWwater activity meter is suited for the measurement of materials like
cereal products, coffee, cocoa, muesli, butter, mixtures of dried fruit, spices, granulates,
mushrooms, sugar, xylitol, biscuits or dry sausages and many other types of food where a
check of the water activity is required.
The humimeter AWis in general not suited for liquids and juices (syrup), acidic food like
onions, fruits and tropical fruits or food and beverages containing alcohol, e.g. filled
chocolates. Vinegar and acids destroy the calibration and the sensor.
Materials with moisture above the fibre saturation point, (this means an awvalue above 1),
cannot be measured. For such materials only the water content can be determined.
Water activity must not be confused with water content –the percentage of water
contained in a product.
The water content is used for billing according to the dry content of food and materials, it
indicates the ratio of water to the total mass in percent (kg/kg x 100).
The water activity influences the following characteristics of a product:
• microbiological stability
• chemical stability
• enzymatic stability
• colour, taste and nutritional value
• content of proteins and vitamins
• stability of composition
• shelf life
• storage and packaging
All forms of life depend on water. The water activity indicates the amount of
water available for microorganisms such as: bacteria, fungi, moulds etc. Each
type of microorganism needs a certain minimum water activity value being
able to grow. A lower water activity value doesn´t allow any growth.

4
Water activity Organism
aw = 0.91...0.95 bacteria
aw = 0.88 yeasts
aw = 0.80 moulds
aw = 0.75 halophilic bacteria
aw = 0.70 osmiophilic yeasts
aw = 0.65 xerophilic mould
Minimum water activity:
Measurement
To switch on the instrument, press the key for
three seconds. After showing the logo, the measuring
window opens and the current awvalue is displayed.
If a different calibration curve is set, select the curve “aw
value” using the or button. The calibration curves
saved in the device can be found in the following list:
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
15.00
16.00
17.00
18.00
19.00
20.00
21.00
22.00
23.00
24.00
25.00
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90
moisture content
AW value
Typical moisture sorption isotherms of different food and materials from the literature
ceramic powder
pulp
wheat
barley
rye

5
Calibration curves
calibration curve
description
unit
measuring
range
awvalue
water activity
aw
0 to 1
rel. humidity
rel. air humidity
%rh
0 to 100%
dew point
dew point
°C / °F
-55 to +60°C
-67 to 140°F
abs. humidity
abs. air humidity
g/m³
0 to 130 g/m³
empty
free curve for own
calibration
%rh
CO2
CO2value
ppm
0 to 5000ppm
IR temperature
temperature
infrared sensor
°C or °F
-25 to 125 °C
-13 to 257 °F
List of calibration curves
Pressing the or key in the measuring
window for at least 3 seconds, a list with all
available calibration curves appears. Select
your sort by pressing or and confirm by
pressing the key.

6
Application range
Within the normal application range (normal range) the accuracy of the device
is as indicated. A long-term application beyond the normal application range
(max. range), particularly at an air humidity of more than 80%, can lead to
higher measuring errors (+3% after 60 hours). Back in the normal application
range, the sensor will return to the indicated accuracy automatically.
Other instrument functions –overview
Manual saving of single measuring values in a measurement series
Display of measuring series and measuring values directly on the
instrument
Printing the saved measuring series (only with PC interface and printer)
Transfer and saving of measuring series on a PC (only with PC
interface)
Automatic single-point adjustment with 50% humidity standard
Selection of menu language (DE, EN, FR, IT, ES, RU)
Display of temperature in Celsius or Fahrenheit

7
Design of the device
Options
Connection
To sensors
calibration
curve
temperature
ON/OFF button
measurement
selection of
sensor type
batteries slot
(flipside)
Moisture & Temperature
Sensor (Part#: HM-
12032)
Precision Rel. Humidity
& Temperature Sensor
(Part#: HM-12004)
Air Humidity &
Temperature Sensor
AwSensor
Connecting Plug
Aw Sensor
(Part#: HM-
13700)
Connecting Plug

8
Menu level overview
Type selection menu
Next calibration curve
Previous calibration curve
Power off
Store menu
Show last log
Store new log
Power off
Main menu
Switch lower
Switch upper
Open this menu/enter
Edit Logs
Options
Manual Logs
Date/Time
Auto Logs
Datalog Time
Clear Logs
Language
Unlock
Print Logs
°C/°F
Last Logs
User level
All Logs
BL On Time
Clear Logs
Auto Off Time
Send Logs
Calibrate
Material calib.
Manual Logs
Online Send
Auto Logs
Online Print
Clear Logs
Adjust
Password
Reset
Status
Keypad symbols
Measuring window:
Rolling Menu
Power ON / OFF
Switch upper
Switch lower
Save
Hold
Autolog
Watch saved data
Enter
supplier´s data
Menu:
Enter
Switch upper
Switch lower
Exit
Enter numbers
Enter letters
Next or right
Left
Yes
No
Shift
OK

9
Operating the instrument
Switching on: Press for three seconds.
Changing the calibration curve: or .
Setting date and time: two times - Options –date / time
Set date and time using the button , according to the format indicated
(JJ.MM.TT). After entering the year, press the button for entering the
month and again for entering the day. For changing from date to time also
press the button . After finishing, press for saving the entered data.
Datalog: Select your desired interval in the menu Options –Log Time using
the arrow keys, and confirm by pressing OK. Now in the store menu appears
the symbol . By pressing this symbol you can activate the
AutoLog.
Info: In order to save battery power, the device switches off automatically after an
interval of 1 minute or longer; and then activates again for saving the logs!
For completing the AutoLog, switch on the device (if necessary) and press
the button. If you want to add supplier´s data please press the
button. Supplier´s Lot/Product data can also be entered on the PC
subsequently.
Switching on the display lighting: Press the key briefly; the display
lighting switches off automatically after approx. 20 seconds. Pressing any
key activates the display lighting again, and the period for switching off again
is prolonged to 4 minutes (The display lighting time can be modified in menu
level Options –BL On Time).
Switching off: Press the key for five seconds. The instrument switches
off after releasing the key. The instrument switches off automatically after
approx. four minutes. (The turn-off time can be modified in menu level
Options –Auto Off Time).

10
Transfer saved data to the PC (NOTE: Only applicable if the HM-12778
humimeter USB data interface module with LogMemorizer)
To send your saved logs to the PC, connect the
humimeter device to your PC using the USB cable
that was delivered with your device. Carefully
loosen the protection cap on your humimeter and
plug in the USB mini B connector. The bigger
connector has to be connected to a USB port on
your PC.
Start the LogMemorizer software on your PC and
switch on your humimeter AW1.
The data transfer can be started on your
humimeter or on the software:
Starting data transfer on the humimeter:
Press the key until you reach the menu (see
image on the right). Then choose “Send Logs” and
confirm by pressing the key. Now choose
“Manual Logs” or “Auto Logs” and confirm with
again. All saved logs will be transferred to your
PC.
Starting data transfer on the PC:
Press the button “remote control” in the
LogMemorizer software. A drop-down menu with
several options opens (see image below).
For transferring the data you can select “Import
last manual log” (the last saved measuring series
is transferred) or “Import all manual logs” (all
saved logs are transferred.
If you click on one of these menu items, the
transfer starts immediately.
For the basic adjustments of the software please
look through the instructions on the LogMemorizer
CD.