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Instruction Manual
Model NGA2000 TO2
with a clean, metallic diaphragm, | Pressure | |
regulator. A shutoff valve is recommended. | Constant between 13.8 and 69 hPa - gauge | |
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Calibration Gases | (0.2 and 1.0 psig) sample inlet pressure is | |
recommended. If a needle valve is used | ||
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The TO2 module does not require routine | upstream of the Analyzer Module to control | |
zero calibration. The zero is factory set and | flow, the inlet pressure to the needle valve | |
does not experience routine drift. Over long | should not exceed 345 hPa (5 psig). A | |
periods of time, the zero may experience | constant sample flow rate between 1.0 to | |
minor drift. For low ppm range analyzers, | 3.0 SCFH (0.5 to 1.5 l/min) is recommended | |
you may wish to check the zero at one year | for best results. The Analyzer Module must | |
intervals. | vent to atmosphere to avoid back pressure | |
mended for use as zero gas. This gas is | influences on the oxygen reading. | |
certified to <0.5 ppm oxygen and can be |
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improved by passing the zero gas through | b. Connections | |
an oxygen scrubber such as Millipore™ |
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Waferpure or Semigas Nanochem® resin | (See Figure | |
purifiers. A mixture of trace oxygen in a | and outlet lines for sample to appropriately | |
background of nitrogen is recommended as | labeled fittings on the rear panel. SAMPLE | |
span gas. For maximum accuracy, the con- | IN and SAMPLE OUT are | |
centration of trace oxygen in the span gas | type compression fittings. Zero and span | |
should be as high as possible for the range | gases should be introduced at the SAMPLE | |
of measurement. | IN fitting at normal sample inlet flow rate. | |
Sample | Metallic tubing is recommended for the | |
The sample must be clean and dry before | sample line. The use of plastic, Teflon, or | |
other | ||
entering the Analyzer Module. Sample | ||
bient oxygen permeation through the tubing | ||
should be filtered for particulates down to | ||
causing higher than expected reading. Ex- | ||
two microns, and should have a dewpoint at | ||
haust tubing should be 1/4 inch (6.3 mm) or | ||
least 5 °C (13 °F) below the coldest ex- | ||
larger, and can be metallic or | ||
pected ambient temperature. | ||
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ANALYZER MODULE | BACKPLANE |
CONNECTIONS | CONNECTIONS |
Network 1 | Backplane |
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Network 2 |
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Power | Controller Board |
| Connector |
Fuse | Network |
Power Indicator Light | |
| Power |
Figure 2-1. Analyzer Module Interconnection with Instrument Platform
Installation | Rosemount Analytical Inc. A Division of Emerson Process Management |