Ametek CEM/Humox, User Manual

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3-4 | Thermox CEM/Humox Analyzer
Figure 3-2.
Cal/Process gas
setup example (no RCU).
OTHER GAS
ANALYZER(S)
CEM/O2
SERIES
2000
CONTROL
VACUUM
TO PULL
SAMPLE
PROCESS
PROCESS/CAL
CONTROL VALVE
CAL
GASES
SAMPLE
Calibration Setup
Figure 3-1 shows the location of the inlet port on the CEM/O
2
sensor. When cali-
brating your system, you will connect calibration gases upstream of this inlet port.
Required calibration gases and tubing
Use calibration gases at between 2 and 20 SCFH (0.94 to 9.4 L/min). Also be sure
that you use the same flow rate for calibrations and daily operations.
The span gas must be a higher oxygen content than the zero gas by a factor of 10
(for example, if zero gas is 1.0%, span gas must be 10% or higher. If zero gas is
.1%, span gas must be 1% or higher).
Span gas - instrument air (20.9%) or from 1.0% to 100% O
2
, balance N
2
.
Zero gas - from .1 to 10% O
2
, balance N
2
(2% is recommended).
Always use tubing that is free of oil and dirt.
Manual calibration connections
We recommend that you insert a control valve before the inlet port of the sensor
(Figure 3-1 shows the location of the sensor gas inlet). Using this valve, you can
easily switch between introducing the sample and calibration gases to the CEM/O
2
sensor as shown in the example on Figure 3-2 .