Teledyne T300, Operation Manual, Page: 102 / 426

Setup Menu Teledyne API – Model T300/T300M CO Analyzer
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5.4.2. PHYSICAL RANGE VS ANALOG OUTPUT REPORTING RANGES
Functionally, the T300 Family of CO Analyzers have one hardware PHYSICAL
RANGE that is capable of determining CO concentrations between across a very wide
array of values.
Table 5-1: T300 Family Physical Range by Model
MODEL RANGE
T300 0 – 1000 ppm
T300M 0 – 5000 ppm
This architecture improves reliability and accuracy by avoiding the need for extra,
switchable, gain-amplification circuitry. Once properly calibrated, the analyzer’s front
panel will accurately report concentrations along the entire span of its physical range.
Because many applications use only a small part of the analyzer’s full physical range,
this can create data resolution problems for most analog recording devices. For
example, in an application where an T300 is being used to measure an expected
concentration of typically less than 50 ppm CO, the full scale of expected values is only
4% of the instrument’s full 1000 ppm measurement range. Unmodified, the
corresponding output signal would also be recorded across only 2.5% of the range of the
recording device.
The T300/T300M Analyzers solve this problem by allowing the user to select a scaled
reporting range for the analog outputs that only includes that portion of the physical
range relevant to the specific application.
Only this REPORTING RANGE of the analog outputs is scaled; the physical range of
the analyzer and the readings displayed on the front panel remain unaltered.
Note Neither the DAS values stored in the CPU’s memory nor the concentration
values reported on the front panel are affected by the settings chosen for
the reporting range(s) of the instrument.
5.4.3. REPORTING RANGE MODES: SINGLE, DUAL, AUTO RANGES
The T300/T300M provides three analog output range modes to choose from.
•
Single range ( SNGL ) mode sets a single maximum range for the analog output. If
single range is selected both outputs are slaved together and will represent the
same measurement span (e.g. 0-50 ppm), however their electronic signal levels
may be configured for different ranges (e.g. 0-10 VDC vs. 0-.1 VDC).
•
Dual range ( DUAL ) allows the A1 and A2 outputs to be configured with different
measurement spans as well as separate electronic signal levels.
•
Auto range ( AUTO ) mode gives the analyzer to ability to output data via a low range
and high range. When this mode is selected the analyzer will automatically switch
between the two ranges dynamically as the concentration value fluctuates.
Range status is also output via the external digital I/O status outputs (See Section
3.3.1.4).
06864B DCN6314