Sample Mode; Test Functions - Teledyne 6400A Instruction Manual

TAI Model 6400A SO Analyzer Operator Manual, 02164, Rev. G
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5.2 Sample Mode

5.2.1 Test Functions

NOTE
In any of the following TEST functions, if XXXX is displayed,
that indicates an off scale and therefore meaningless reading.
To use the TEST functions to diagnose instrument faults, refer to Troubleshooting Section 9.1.
Range
This is the range of the instrument. In standard configuration there is one range for both REC and
DAS outputs.
Dual range allows a different range for each output. When enabled, the RANGE test measurement is
replaced with two different test measurements, RANGE1 (REC) and RANGE2 (DAS).
Auto range option allows a low range and high range. The 6400A will automatically switch to the
other range dynamically as concentration values require. The TEST values will show the range the
instrument is currently operating in, and will dynamically display the alternate range as the range
changes occur.
Stability
The instrument stability is used to indicate the stability of measurement of analyzer. It is computed
as the standard deviation of 25 samples of a moving window with interval of 10 seconds between
each sample. Typical value is 0.1 to 2 ppb when sampling constant concentration of gas.
Pressure
Sample pressure is measured using solid state pressure sensor at the downstream of the reaction cell.
This reading will vary according to the altitude and local weather condition. This reading is used by
the CPU to compensate the SO concentration due to its pressure of the sample gas.
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Sample Flow
A solid state mass flowmeter measures the sample flow which is the weight flow and the reading
will be lower at altitude. (See Section 4.2.7) Its nominal value is 650 ± 65 cc/min.
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