Servomex DF-310E, Operator'S Manual

Page: 76 / 130

72 DF-310E User Interface
Figure 42: Recorder Output Setup Error
8.4.2.2 Scaling Analog Output Range On High Resolution Analyzers
On High-Resolution Analyzers the instrument has two internal operating ranges: 0-10% of full
scale (Scale A) and 0-100% of full scale (Scale B). When the oxygen reading decreases below
10% of full scale the analyzer automatically increases it’s internal gain by a factor of ten by
switching to Scale A. This gain increase permits the front panel oxygen display to provide an
additional digit of displayed resolution. Refer to the section on Specifications page 9, for a list
of displayed resolutions. The increased gain also permits the analog output scaling to be set for
from 10% to 100% of Scale A, in addition to 10% to 100% of Scale B. See Table 15 for details.
Using the High-Resolution model is preferred if the oxygen reading will usually be below 10%
of the analyzer full scale reading and small changes in concentration (0.1% of full scale) must be
detectable. The selected Zero and FS values will be displayed underneath the oxygen reading in
the Data Display Screen. Following are examples of valid recorder output settings on a 0 – 100
ppm high resolution analyzer.
Output (Zero to FS)
Percentage of scale used
on a 0 – 100 ppm high
resolution analyzer
0-1 ppm
2-4 ppm
1-5 ppm
0-10 ppm
0-20 ppm
20-40 ppm
10-50 ppm
0-100 ppm
50-85 ppm
10 % of Scale A
20 % of Scale A
40 % of Scale A
100 % of Scale A
20 % of Scale B
20 % of Scale B
40 % of Scale B
100 % (Factory Set)
35 % of Scale B
Table 15: Output Scaling on High Resolution Analyzer
8.4.2.3 Expanded Range Scale Operation And Setup
The optional expanded range scale function allows the analog output scaling to be automatically
expanded to a larger value when the primary scaling range is exceeded. For example, in the
display shown in Figure 41, the analog outputs (0-10 VDC and 4-20 mA) are scaled over the 0 -
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