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AQUALAB
3.3.2 USING A TERMINAL PROGRAM
There are several terminal program options. METER has its own terminal program
(DecaTerm) that can be downloaded from software.metergroup.com. Two other options
are TeraTerm, a free program that can be found on the internet, and Hyperterminal, the
standard program with Microsoft Windows prior to Windows 7 software.
To integrate a terminal program with AQUALAB, use the following steps:
1. Power on the AQUALAB.
2. Connect the USB interface cable to the computer.
3. Follow the instructions for the program with the following settings:
c. Choose correct COM Port
d. Set or verify COM Properties
e. Bits per second (Baud rate): 9600
Data: 8 bit
Parity: none
Stop: 1 bit
Flow control: none
Upon successful completion of a water activity reading, the data in the terminal program
displays measurement time (in minutes), sample temperature, and water activity. Table
3 shows an example data return.
Table 3 Terminal data
Measurement
Time
Temperature
(ºC)
a
w
3.1 24.3 0.862
3.4 THEORY
Water is a major component of foods, pharmaceuticals, and cosmetics and influences the
product texture, appearance, flavor, and shelf life. Quantifying these attributes require
two basic types of water analysis: moisture content and water activity (a
w
).
3.4.1 MOISTURE CONTENT
Moisture content implies a quantitative analysis to determine the total amount of water
present in a sample. There are two primary methods for determining moisture content:
loss on drying and Karl Fisher titration. Secondary methods, such as near infrared
(NIR) and nuclear magnetic resonance (NMR), may also be used. Moisture content
determination is essential in meeting product nutritional labeling regulations, specifying
recipes, and monitoring processes.
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