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 37
Note: Changing the offset setting will affect past data already stored to memory. Always download any old data before
changing settings, then clear the memory. Firmware version 3.2.4 or later will prompt you to clear the memory before
letting you change this setting.
CONC UNITS: This setting determines the concentration units which the APDA-371 displays and stores in memory.
This can be set to ug/m3 (micrograms) or mg/m3 (milligrams) per cubic meter. This is a new option for the APDA-371.
Past versions have always been set for mg/m3. Note: 1 mg = 1000 g.
COUNT TIME: This is the amount of time the unit takes to perform the I
0
and I
3
counts. Past versions of the APDA-371
have always been fixed at 4 minutes. The new options allow the count time to be set for 4, 6 or 8 minutes. When used
to monitor PM
2.5
, this must be set to 8 minutes. This increases the sensitivity of the unit in lower concentrations.
Increasing the count time will require decreasing the sample time. For example, a count time of 4 minutes allows a
sample time of 50 minutes, while a count time of 8 minutes allows a sample time of only 42 minutes. The unit will
prompt you to change the sample time if you change the count time to an incompatible value.
6.3
CALIBRATE Screen – Critical Information
The SETUP > CALIBRATE screen is where most of the factory-determined calibration parameters for the APDA-371
are stored. These values are unit-specific, and can also be found on the calibration certificate for the unit in case a
setting is accidentally changed. Most of these settings will never be changed without specific information from HORIBA.
It is good practice to periodically audit the calibration values to verify that they have not been altered. The CALIBRATE
screen is shown below.
CALIBRATE SETUP
FLOW RATE: 16.7
CONC TYPE: ACTUAL FLOW TYPE: ACTUAL
Cv: 1.047 Qo: 0.000
ABS: 0.822 µsw: 0.306
K: 1.005 BKGD: -0.0030
STD TEMP: 25C HEATER: AUTO
SAVE EXIT
The SETUP > CALIBRATE Screen
FLOW RATE: This sets the air flow rate for the APDA-371 sample period. The APDA will continuously regulate the
flow to this value (except manual valve models). The flow rate is almost always set for 16.7 liters per minute, as this is
required for all PM
2.5
and PM
10
monitoring. The operator may change this value temporarily in order to test the ability of
the pump and flow controller to regulate the flow at different levels. The range of this setting is 10 to 20 LPM.
CONC TYPE: This sets the way that the concentration values are reported. If set to ACTUAL, then the concentration
is calculated based on the volume of the air at ambient conditions, and a BX-592 or BX-596 temperature sensor is
required. If set to STD, the concentration is calculated based on the standard values for temperature and pressure
(usually 25C and 760mmHg), even if a temperature sensor is available. This value is usually set to match the FLOW
TYPE setting, and must be set to ACTUAL for PM
2.5
monitoring. Note: APDA units with firmware prior to rev 3.0 does
not have this setting available.
FLOW TYPE: This setting selects the flow control scheme used by the APDA-371. The three possible settings are
METERED, STD, and ACTUAL.
•
METERED:
Usually used for APDA units with a manual flow valve on the back. Flow is reported in EPA
conditions.
•
STD:
EPA Standard flow. The flow is controlled and reported in EPA standard conditions. Used
where required by regulations.
•
ACTUAL:
Actual Volumetric flow is controlled and reported to ambient temperature and pressure
conditions. This is required on PM
2.5
monitors, and is recommended by HORIBA whenever possible. BX-596 or
BX-592 sensor is required.