Filter
Top Products
Model 360E Instruction Manual Operating Instructions
6.8. SETUP RNGE: Analog Output Reporting Range
Configuration
The analyzer has three active analog output signals, accessible through a connector on the rear panel.
Test Channel
A
NALOG OUT
A1 A2
A
3
A
4
+ - + - + - + -
CO
2
concentration
outputs
HIGH range when DUAL
mode is selected
Not Used
LOW range when DUAL
mode is selected
Figure 6-7: Analog Output Connector Pin Out
All three outputs can be configured either at the factory or by the user for full scale outputs of 0.1 VDC, 1VDC,
5VDC or 10VDC. Additionally A1 and A2 may be equipped with optional 0-20 mADC current loop drivers and
configured for any current output within that range (e.g. 0-20, 2-20, 4-20, etc.). The user may also adjust the
signal level and scaling of the actual output voltage or current to match the input requirements of the recorder or
data logger (See Section 6.13.4).
The A1 and A2 channels output a signal that is proportional to the CO
2
concentration of the sample gas.
Several modes are available which allow them to operate independently or be slaved together (See Section 6.7).
The user may also select between a variety of reporting range spans (See Sections 6.8.3, 6.8.4 and 6.8.5).
EXAMPLE:
A1 OUTPUT: Output Signal = 0-5 VDC representing 0-1000 ppm concentration values
A2 OUTPUT: Output Signal = 0 – 10 VDC representing 0-500 ppm concentration values.
Output A3 is only active if the O
2
sensor option is installed. In this case a signal representing the currently
measured O
2
concentration is output on this channel.
The output, labeled A4 is special. It can be set by the user (See Section 6.13.9) to output several of the test
functions accessible through the <TST TST> keys of the units sample display.
6.8.1. Physical Range versus Analog Output Reporting Ranges
Functionally, the Model 360E Gas Filter Correlation CO
2
Analyzer has one hardware Physical Range that is
capable of determining CO
2
concentrations between 50 ppb and 2,000 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 50 ppb and
2,000 ppm physical range.
Because, most applications use only a small part of the analyzer’s physical range, the width of the Model 360E’s
physical range can create data resolution problems for most analog recording devices. For example, in an
application where the expected concentration of CO
2
is typically less than 500 ppm, the full scale of expected
values is only 25% of the instrument’s 2,000 ppm physical range. Unmodified, the corresponding output signal
would also be recorded across only 25% of the range of the recording device.
05232 Rev B3 77