Teledyne 316RA / RB / RAD / RBD - Oxygen analyzers - Manual (Page 7)

TELEDYNE ANALYTICAL INSTRUMENTS
3
Trace Oxygen Analyzer Model 316RA/RB/RAD/RBD
Operational Theory
Micro-Fuel Cell Sensor
The Series 316 uses a Micro-Fuel Cell for the measurement of trace
oxygen. This Micro-Fuel Cell is an electrochemical transducer whose
features include:
• Specificity for oxygen
• Long interval between calibration
• Long life
• Low maintenance
• Disposable configuration
The transducer functions as a fuel cell; in this instance, the fuel is
oxygen. Oxygen diffusing into the cell reacts chemically to produce an
electrical current that is proportional to the oxygen concentration in the gas
phase immediately adjacent to the cell’s sensing surface.
Sampling System
The Series 316 contains a throttle valve and flowmeter for sample
path flow control as shown on the Piping Diagram (dwg. B-9051). The
integral flow path also features a shutoff valve located downstream from
the Micro-Fuel Cell manifold. When closed, these two valves isolate the
cell from the high oxygen concentration of air. Before shipment, the
sample system is purged with either the customer’s background gas (when
practical) or an inert gas, such as nitrogen. When the instrument shows a
stable, low ppm oxygen level, the two valves are closed, maintaining the
cell in a virtually oxygen-free atmosphere until the instrument is installed
and ready for use.
NOTE: To shorten start-up time and conserve cell use, keep the two cell
valves closed until installation is complete and sample is flowing.