Preparations for Use
–
CIRAS-2 Operator's Manual Version 2.04
- 20 -
Step 4. Connect leaf cuvette power cable to external 12V DC Power Supply
(Optional)
- All automatic style leaf cuvettes are supplied with a power supply cable which allows you to
power the cuvette (temperature and light control) from an external 12V battery or 12V DC regulated power
supply if required. One end of the cable has alligator-style clips (red/positive and black/negative) for
connection to a 12V battery or power supply. The other end has a white plastic socket which connects to
the white plastic plug on the leaf cuvette cable. For example, if your CIRAS-2 system includes a PLC5(C)
Conifer Cuvette with the LED light unit, then you must connect to external power due to the additional
voltage requirements of the conifer cuvette.
Step 5. Inspect absorber columns and water vapor equilibrator
Absorber columns are labelled on the bottom of the CIRAS-2 console as follows:
MS
Molecular Sieve
D
Drier (Envirogel)
SL
Soda Lime
All chemicals should be fresh and columns firmly seated in the correct manifold ports as follows:
Column Chemical
When fresh, chemical is:
When exhausted,
chemical is:
1
1/3
rd
Molecular Sieve
2/3
rd
Envirogel
White (Non-Indicating)
Orange
White (Non-Indicating)
Green
2
Soda Lime
Green
Brown
3
Soda Lime
Green
Brown
4
1/3
rd
Molecular Sieve
2/3
rd
Envirogel
White (Non-Indicating)
Orange
White (Non-Indicating)
Green
5
Envirogel
Orange
Green
When any of the desiccants are approximately 2/3
rd
exhausted (e.g. when soda lime is 2/3
rd
brown), the
entire contents of the absorber column should be replaced.
Please note: Molecular sieve desiccant is non-indicating and does not change color when
exhausted. Therefore, the general rule is that you should ALWAYS change this desiccant when
the Envirogel desiccant (in the same column) is 2/3
rd
exhausted.
Important Note:
Until June 2003, we used a desiccant called “Drierite” instead of Envirogel. Both work
similarly, but the layout of the CIRAS-2 absorber columns is slightly different. For more information on the
layout of absorber columns based on the different drier desiccants, please visit our Users webpage and
download the application note titled “Use of Drierite And Envirogel With CIRAS-1 and CIRAS-2”.
Inspect absorber column end caps and ensure they are correctly seated and that the sealing “O” rings
have not rolled out of position. The Water Vapor Equilibrator should be inspected to ensure that it is firmly
seated in its manifold. An image and description of the absorber columns can be seen below.
