Physical And Analog Output Ranges; Reporting Range Modes - Teledyne 200E Instruction Manual

Model 200E Instruction Manual
A1 OUTPUT (NO
A2 OUTPUT (NO): Output Signal = 4-20 mA (with current loop option)
A3 OUTPUT(NO
Output A4 can be set by the user to report one of many of the parameters accessible
through the <TST> keys of the unit's SAMPLE mode display. A4 is not available for the
current loop option.

6.5.1. Physical and Analog Output Ranges

Functionally, the model 200E NO
and NO concentrations. The difference between the two physical ranges is the resolution of
2
the output signals from the preamplifier board. Internally, the analyzer's signal resolution is
about 16-bit or 72000 counts per 5 V PMT signal. The low range spans 0 to 2000 ppb NO
(2000 ppb = 5 V) whereas the high range spans 0-20000 ppb NO
ranges need to be calibrated independently to the same span gases in order to allow
switching back and forth between high and low ranges. Once properly calibrated, the
analyzer's front panel will accurately report concentrations between 0 and 20000 ppb,
regardless of the selected analog range. To switch between physical ranges, the user has to
specify an appropriate analog output range from the front panel. Any analog range between
0 and 2000 ppb will cause the analyzer to remain in the low physical range. Any upper
analog range limit between 2001 and 20000 ppb will cause the instrument to operate in its
high physical range.
For applications using chart recorders or other analog recording devices, such a wide range
can usually not be resolved on the output. For example, in an application where the
expected concentrations of NO, NO
of expected values is only 0.25% of the instrument's 20000 ppb physical range. The
corresponding output signal would then only be recorded across 0.25% of the range of the
recording device.
The M200E solves this problem by allowing the user to select a reporting range for the
analog outputs that only includes that portion of the physical range that covers the specific
application. Note that only the reporting range of the analog outputs is scaled, the physical
ranges of the analyzer remain unaltered with the exception of the 2000/2001 ppb split. This
increases the reliability and accuracy of the analyzer by avoiding additional gain-amplifica-
tion circuitry. If properly calibrated, both the iDAS values and the concentration values on
the front panel are also unaffected by any change in analog output ranges.

6.5.2. Reporting Range Modes

The M200E provides three analog output range modes to choose from.
• Single range mode (SNGL) sets all measured gases to the same output reporting
range.
• Independent range mode (IND) allows the reporting ranges for all gases to be
different.
044100102 Rev A
): Output Signal = 0-5 V
x
): Output Signal = 0 - 1 V
2
analyzer has two physical ranges for determining NO
x
and NO
2
are typically less than 500 ppb, the full scale
x
Operating Instructions
(20000 ppb = 5 V). Both
X
, NO
x
X
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