Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 135)

Operating Instructions Model 9110TH NOx Analyzer
Teledyne Analytical Instruments 115
Additionally A1, A2 andA3 may be equipped with optional 0-20 mA current loop
drivers. A4 is not available for the current loop option.
Table 4-19: Analog Output Current Loop Range
RANGE MINIMUM OUTPUT MAXIMUM OUTPUT
0-20 mA 0 mA 20 mA
These are the physical limits of the current loop modules, typical applications use 2-20 or 4-20 mA for the
lower and upper limits. Please specify desired range when ordering this option. The default offset for all
ranges is 0 mA.
All of these outputs can be configured output signals representing any of the DAS
parameters available on this model (See Table A-6 of Appendix A.5 for a complete list).
The ability to select any one of the 9110TH/M’s 40+ DAS data types coupled with the
ability to select from a variety of signal ranges and scales makes the analog outputs of
the 9110TH/M extremely flexible.
Table 4-20: Example of Analog Output Configuration for 9110TH/M
4.13.4.2. Physical Range versus Analog Output Reporting Ranges
The entire measurement range of the analyzer is quite large, 0 – 5,000 ppm for the
9110TH and 0-200 PPM for the 9110TM, but many applications use only a small part of
the analyzer’s full measurement range. This creates two performance challenges:
1. The width of the analyzer’s physical range can create data resolution problems for
most analog recording devices. For example, in an application where a 9110TH is
being used to measure an expected concentration of typically less than 200 ppm
NO
x
, the full scale of expected values is only 4% of the instrument’s full 5000 ppm
measurement range. Unmodified, the corresponding output signal would also be
recorded across only 4% of the range of the recording device.
The 9110TH/M 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.
2. Applications where low concentrations of NO, NO
2
and NO
x
are measured require
greater sensitivity and resolution than typically necessary for measurements of
higher concentrations.
The 9110TH/M solves this issue by using two hardware physical ranges that cover
the instruments entire measurement range The analyzer’s software automatically
OUTPUT
DAS
PARAMETER
ASSIGNED
SIGNAL
SCALE
A1 NXCNC1 0-5 V
A2 N2CNC2 4-20 mA 1
A3 PMTDET 0 - 1 V
A4 O2CONC 0-10 V
1 With current loop option installed