MIRI
®
TL family`s multiroom IVF incubators User Manual Rev. 1.0
93
Measure the N
2
concentration in the gas supply by routing the gas line into a bottle
without a lid and a suitably large opening. Set the pressure/flow so that the bottle is
flushed continually with gas, without increasing pressure in the bottle (i.e., the amount of
gas exiting the bottle should be equal to the gas volume entering the bottle).
Sample from the bottle near the bottom with the gas analyzer.
A gas analyzer that can measure 0% O
2
accurately can be used. 100% N
2
= 0%
O
2
.
PASS: N
2
concentration measured must be between 95.0%
–
100%.
The use of N
2
gas with moisture will damage the flow sensors. Moisture level
must be verified on the gas manufacturer's certificate: only 0.0 ppm v/v Max is
permissible.
35.2.1 About N
2
Nitrogen makes up a significant portion of the earth's atmosphere with 78.08% by
volume. Nitrogen is a colourless, odourless, tasteless, non-toxic, and almost inert gas.
Nitrogen is principally shipped and used in either gaseous or liquid form.
N
2
gas can act as a simple asphyxiant by displacing air.
The User should make sure the N
2
used is safe and moisture-free. Below is a list of some
standard component concentrations. Please note that the values given are NOT the proper
amounts, only an example:
•
Research Grade 99.9995%.
•
Contaminant.
•
Argon (Ar) 5.0 ppm.
•
Carbon Dioxide (CO
2
) 1.0 ppm.
•
Carbon Monoxide (CO) 1.0 ppm.
•
Hydrogen (H
2
) 0.5 ppm.
•
Methane 0.5 ppm.
•
Oxygen (O
2
) 0.5 ppm.
•
Water (H
2
0) 0.5 ppm.
35.3 CO
2
gas pressure check
The MIRI
®
TL6 and MIRI
®
TL12 multiroom IVF incubator require a pressure of 0.4 – 0.6
bar (5.80 – 8.70 PSI) on the input CO
2
gas line. This gas pressure must be held stable at all