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Operation Manual HORIBA APDA-371
Particulate Monitor
Date:
April, 2010
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HORIBA Europe GmbH, Julius-Kronenberg-Str. 9, D-42799 Leichlingen, Telefon: +49(0)2175-8978-0, Fax: +49(0)2175-8978-50
Page 55
8
EXTERNAL DATALOGGER INTERFACE SYSTEM
This section describes the configuration of the APDA-371 to work with a separate, external datalogger. The APDA-371
provides an analog concentration output voltage, as well as an array of relay inputs and outputs. These allow the
APDA-371 to function as a sensor in a larger array of data collection instruments. There are a variety of dataloggers
available which are compatible with the APDA-371 outputs, so consult the manual for your datalogger for the specific
setup requirements.
8.1
Analog Concentration Output Signal
The primary link between the APDA-371 and an external datalogger is the analog concentration output signal. The
analog output type is selectable between isolated voltage (0-1 or 0-10 volt DC) and isolated current (4-20 or 0-16 mA).
The rear panel dipswitches are used to select the output as shown in the table below. The one-volt range is by far the
most common. The full-scale value of the output voltage corresponds to the full-scale measurement of the APDA-371,
determined by the RANGE and OFFSET setting. See Section 6.2. In the majority of applications, the analog output is
set for 0-1 volt = 0 to 1.000mg or 0-1 volt = -.005 to .995mg. If the OFFSET is set to -0.015 for PM
2.5
, then the analog
output is 0-1 volt = -.015 to .985mg. The analog output should be tested as described in Section 7.12.
SWITCH
ON
OFF
SW1
0-10 vdc
0-1 vdc
SW2
4-20mA
0-16mA
SW3
Not used
Not used
SW4
Not used
Not used
In most cases the analog output is the only channel available between the APDA-371 and the datalogger, and any
errors generated by the APDA must be reported using the same voltage signal. The APDA-371 will set the analog
output to its full-scale reading when any of the selected errors occur. The errors which cause this are selectable, and
are described in section 6.5. The external datalogger should be programmed to recognize a full-scale reading as an
error, not a valid concentration. This method is used because it is very rare for a concentration reading to exceed the
range of the APDA-371. The digital data values stored in the APDA are unaffected and may be viewed with the display
or by downloading.