CGA 351

Panametrics zirconiumoxide oxygen analyzer
Features• Fast, easy one-point calibration• Low maintenance• Measures oxygen from 0.1 ppm to 100 percent; canmeasure oxygen in reducing gases

Trace O2 applications
This full-featured oxygen analyzer is typically used inapplications such as:• Air separation plants• Glove boxes• Fast response (90 percent of step change in lessthan 2 seconds)• Semiconductor manufacturing processes• Extremely stable sensor operation• Glass and ceramic research• Months of trouble-free service; calibration checks oradjustments seldom required; one-point calibration issufficient for entire range from ppm to percent oxygen• Inert gas purity• Accuracy increases at low oxygen concentrations• Heat treat and metallurgical processes• Blanket gas monitoring• Medical research• Gas blending

Special applications• Welding atmospheres• Gas generators• Air/fuel mixtures

Wall mount version of CGA 351

How it works

Panametrics zirconium oxide oxygen analyzer

Sample gas enters the inlet port through a needle valve
and flows into a ceramic inlet tube. It then flows through theannular space between the inlet tube and the inside of thezirconium oxide oxygen sensor, then out through the outlet
port and a flowmeter. When there are no combustibles
present in the sample gas, the analyzer measures total
oxygen. When combustibles are present, a platinum-based
catalyst at the end of the ceramic tube ensures that thesample reaches equilibrium before contacting the innerelectrode. It is therefore possible to measure either oxygen
excess or deficiency in air/fuel mixtures.

The CGA 351 zirconium oxide oxygen analyzer uses anadvanced zirconia sensor to accurately determine oxygen
content in process gases. Microprocessor-based electronics
allow measurements from ppm levels to 100 percent oxygen.

The zirconium oxide sensor is heated and closely controlled
at 1292°F (700°C). As the sample contacts the inner electrodeof the heated sensor, an electrical signal is generated. The
signal is proportional to the logarithm of the ratio of theoxygen concentration in the sample gas to the oxygen
concentration in a reference gas contacting the outerelectrode. The electronics displays O2 in ppm or percent. It
also displays other parameters including O2 sensor millivoltsand sensor temperature in °F or °C. Ambient air is used as thereference gas on the outside of the electrochemical cell.

Applications and uses
The CGA 351 zirconium oxide oxygen analyzer is suitable formonitoring and/or controlling high purity gas streams oratmospheres such as in air separation, heat treating, ceramic
manufacturing and other processes. For dirty or wet gas
applications, a suitable sampling system may be required.

CGA 351 specifications
Performance
Accuracy
0.2 ppm from 0 to 10 ppm or ±2% of readingRepeatability±1% of reading
Response timeLess than 2 seconds for 90% step change
Stability
Less than 3% of reading per year
Pressure effectLess than 0.2% of reading per mm Hg
Sample flow rate influence
Per 40 cc/min flow change at 400 cc/min
0.2 ppm from 0 to 10 ppm or2% of reading
Background gas variation effectSample gas must be clean, dry and free of combustibles.
For best results used same background gas forcalibration. Standard factory calibration is 5 ppm O2in N2.

Operating
Measurement range• Standard factory setup is 0 to 10 ppm for 4 to 20 mA
output. Field selectable for any portion of the range
from 0.1 to 10 ppm O2• 0.1 ppm to 100% O2• The digital panel meter is software configurable todisplay the following parameters:– Oxygen (ppm or %)– Temperature (°F or °C)– Sensor (mV)
– CJC temperature (°F or °C)

Wall mount version of CGA 351. Dimensions in inches (mm).

Communications
TM

Standard RS232 serial port, PanaView
Sample requirements• Sample flow: 400 cc/min (± 40 cc/min recommended)• Sample inlet pressure: 1 to 10 psig• Sample outlet (vent) pressure: 1 atmosphere
Ambient requirements• Relative humidity: 90% maximum• Temperature range: -13°F to 122°F (-25°C to 50°C)
Power
100/115/220/240 VAC, 50 to 60 Hz, 900 W maximum• Field selection of autorange

Line-voltage influence

Output ranges
0/4 to 20 mA, 0 to 2 V±10% nominal line voltage

Alarm circuits• Dual alarm contacts• Contact rating 2 A, 28 VDC, SPDT, fail-safe

read onlyFuse
4 A, 250 V, TD, 5 x 20 mm
Materials contacting sample gas
316 stainless steel, ceramic and platinumOrdering information

Connections• Sample inlet and outlet: 6 mm compression or ¼ incompression tube fitting

Record selected option in blank indicated at bottom of form.

• Electrical analyzer and D/O unit: 1/2 inch conduit

CGA 351 zirconium oxide oxygen analyzer

Dimensions• Sensor enclosure: 7.0 in x 11.0 in (178 mm x 279 mm)• Electronics enclosure: 6.75 in x 8.0 in (171 mm x 203 mm)

Power
1 100 VAC, 50 to 60 Hz
2 115 VAC, 50 to 60 Hz
3 220 VAC, 50 to 60 Hz
4 240 VAC, 50 to 60 Hz

Warm-up time
• 45 minutes nominalPackage
1 Wall mount• Calibration at alarm or control level with certified
mixtures of O2 in N2

2 Rack mountConnections

European compliance
Complies with EMC Directive 2014/30/EU, LV Directive(overvoltage category II, pollution degree

1 1/4 in tube fitting
2 6 mm tube fittingSpecial0 None
S Special (consult factory)
CGA 351: _ _ _ Use this number to order product

Rack mount version of CGA 351

Panametrics, a Baker Hughes Business, provides solutions in
the toughest applications and environments for moisture,oxygen, liquid and gas flow measurement. Experts in flaremanagement, Panametrics technology also reduces flareemissions and optimizes performance.
With a reach that extends across the globe, Panametrics’
critical measurement solutions and flare emissions
management are enabling customers to drive efficiency
and achieve carbon reduction targets across criticalindustries including: Oil & Gas; Energy; Healthcare; Water andWastewater; Chemical Processing; Food & Beverage andmany others.
Join the conversation and follow us on LinkedIN
linkedin.com/company/panametricscompany

Copyright 2021 Baker Hughes Company. All rights reserved.
BHCS38784(02/2021)

panametrics.com