User Guide
Operating Instructions Teledyne API M100E Analyzer Operation Manual
86
6.7.2. PHYSICAL RANGE VERSUS ANALOG OUTPUT REPORTING
RANGES
The entire measurement range of the M100E is 0 – 20,000 ppb, but many applications use only a small part of
the analyzer’s full measurement range. This creates two performance challenges:
The width of the M100E’s physical range can create data resolution problems for most analog recording
devices. For example, in an application where the expected concentration of SO
2
is typically less than
500 ppb, the full scale of expected values is only 0.25% of the instrument’s full 20,000 ppb measurement
range. Unmodified, the corresponding output signal would also be recorded across only 0.25% of the
range of the recording device.
The M100E solves 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 the
reporting range of the analog outputs is scaled, the physical range of the analyzer and the readings
displayed on the front panel remain unaltered.
Applications where low concentrations of SO
2
are measured require greater sensitivity and resolution than
typically necessary for measurements of higher concentrations.
The M100E solves this issue by using two hardware physical ranges that cover the instruments entire 0
and 20,000 ppb measurement range: a 0 to 2,000 ppb physical range for increased sensitivity and
resolution when measuring very low SO
2
concentrations, and a 0 to 20,000 ppb physical range for
measuring higher SO
2
concentrations.
The analyzer’s software automatically selects which physical range is in effect based on the analog output
reporting range selected by the user.
If the high end of the selected reporting range is 2,000 ppb. The low physical range is selected.
If the high end of the selected reporting range is 2,001 ppb. The high physical range is selected.
Once properly calibrated, the analyzer’s front panel will accurately report concentrations along the entire span of
its 0 and 20,000 ppb physical range regardless of which reporting range has been selected for the analog
outputs and which physical range is being used by the instruments software.
04515F DCN6048