Teledyne GFC-7001E - Trace CO Analyzer - Manual (Page 97)

Basic Operation Model GFC7001E Carbon Dioxide Analyzer
Teledyne Analytical Instruments 97
6.6. SETUP  RNGE: ANALOG OUTPUT REPORTING RANGE
CONFIGURATION
6.6.1. PHYSICAL RANGE VERSUS ANALOG OUTPUT REPORTING
RANGES
Functionally, the GFC 7001E 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 6-7: GFC 7001E Family Physical range by Model
MODEL RANGE
GFC 7001E 0 – 1000 ppm
GFC 7001EM 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 GFC 7001E 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 GFC 7001E/EM 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
Both the iDAS values stored in the CPU’s memory and the concentration values reported on the front
panel are unaffected by the settings chosen for the reporting range(s) of the instrument.