will go off, and the display will indicate the actual CO
2
concentration. If more than one alarm value or level
is to be changed, repeat this procedure on the desired alarm channel.
3.3.6
Timing out during Alarm Setting
If the user is adjusting the alarm values and levels in the Series 9510 Carbon Dioxide Analyzer and no
adjustment has been made for approximately 2 minutes, the analyzer will automatically revert back to
normal operation. This feature helps to prevent the user from inadvertently keeping the analyzer off-line
for a prolonged period of time. If the user is in an alarm setting sequence and the instrument times out,
the alarm value will be that which was last displayed in the LCD.
3.4
Sample Gas Handling
3.4.1 Sample Connections
The Series 9510 Carbon Dioxide Analyzer is normally equipped with either quick connect sample gas
fittings or 1/4” SS compression fittings on the sample input. An open diffuser sensor configuration is
available. These fittings are designed to be used with 1/4” OD plastic tubing in the case of the quick
connect or ¼ “ metal tubing. The CO
2
sensor used in the Series 9510 is a partial pressure measuring
device and any changes to the total pressure will affect each of the partial pressures of the sample gas,
CO
2
being one. Fluctuations in sample pressure are not corrected for and could lead to an error in the
CO
2
measurement.
3.4.2 Gas System Pressure and Flow Limits
For sample gases and/or calibration gases that are under pressure, it is imperative that the input pressure
to the sensor be kept under 2 pounds per square inch (PSI). If the pressure is expected to be in excess of
2 psi, it is advisable to use a pressure regulator (Alpha Omega Instruments Model Number 9PRR or
9LPR). Flow rates through the analyzer should be between 100 to 300 milliliters per minute (ml/min.) for
precent systems and approximately 150 millimeters a minute for trace systems.
If the sample flow is insufficient to move the sample gas through the analyzer housing, a diaphra gm
sample pump may be required (Alpha Omega Instruments P/N
9PMP
). The 9PMP has been designed to
provide dampening of the sample to eliminate fluctuations in CO
2
readings due to pump pulsations. Alpha
Omega Instruments does not recommend the use of any other type of diaphra gm pump unless provisions
for dampening have been included.
3.4.3 Corrosive Gases
For applications where the sample contains corrosive gases, please check with the factory prior to
start-up.
3.4.4 Radioactive Sample Gases
Radioactive sample gases will attack the rubber sample tubing within the analyzer, causing deterioration
at a rate proportional to the level of radioactivity. In applications where radioactive sample gasses are
handled, the internal tubing must be examined periodically and replaced when required. Failure to
observe this precaution could result in leakage of radioactive sample into the ambient atmosphere
3.4.5 Condensible Gas Constituents
In order to provide accurate and repeatable data, it is
essential
that the carbon dioxide sensor not be
exposed to condensed water vapor or any other liquid. The dew point temperature of the sample gas
should always be less than that of the NDIR sensor, thus preventing condensation of water vapor on the
optics within the sensor. If it is anticipated that the sample gas may be saturated with water vapor,
provisions should be make to remove the water by filtration / coalescing, refrigeration, vortex cooling, etc.
Consult Alpha Omega Instruments Corp for more information on this subject.
ALPHA OMEGA INSTRUMENTS CORP.
SERIES 9510 CARBON DIOXIDE ANALYZER INSTRUCTION MANUAL
17
