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 33
5.8
Field Calibration of Flow System – Metered Flow Mode
Metered flow calibration is only performed on APDA-371 units which have a hand-operated manual flow valve on the
back (mostly older units). Because these units do not have automatic flow control, the calibration procedure is much
more complicated. The flow must also be more frequently checked due to changes in ambient conditions, which these
type of units cannot compensate for. Use the following steps for a full Metered flow calibration. The full calibration only
needs to be done once in a while, but the flow should be checked and adjusted often. The process is faster if your
reference flow meter can provide standard flow.
1.
Advance the filter tape to a fresh spot.
2.
Enter the SETUP > CALIBRATE menu. Set the C
v
(coefficient of variability) value to 1.000, and the Q
0
(flow
zero correction) value to 0.000.
3.
Disconnect the pump tubing from the back of the APDA, and turn the pump on in the TEST > PUMP menu.
There will not be any air flowing through the unit. Record the flow reading from the APDA display. This is the
zero flow Z
f
value.
4.
Re-enter the SETUP > CALIBRATE menu and set the Q
0
value to equal the negative of the zero flow value Z
f
.
5.
Go back to the TEST > PUMP menu and turn the pump back on. Verify that the flow reading on the APDA
display now reads 0.0 LPM +/-0.1LPM.
6.
Reconnect the pump tubing to the back of the APDA. Remove any PM
10
and PM
2.5
heads, and connect your
reference flow meter to the inlet.
7.
Record the ambient temperature T
a
(Kelvin) from your reference standard, and record the barometric pressure
P
a
(mmHg) from the OPERATE > NORMAL screen on the APDA.
8.
From the TEST > PUMP menu, turn the pump on and allow the flow to stabilize for 5 minutes. Then record the
actual flow from your reference flow meter Q
a
, and record the standard flow reading from the APDA display Q
b
.
8.
Convert the volumetric flow rate Q
a
from your reference meter to EPA standard flow Q
s
with the following
formula:
Q
s
= Q
a
* (P
a
/ T
a
) * (298 / 760)
T
a
= Ambient Temperature (Kelvin) (Kelvin = C 273)
P
a
= Ambient Barometric Pressure (mmHg)
Q
a
= Actual Volumetric Flow from Reference Meter
9.
Calculate the final value for C
v
:
C
v
= Q
s
/ Q
b
10.
Calculate the final value for Q
0
:
Q
0
= -C
v
* Z
f
11.
In the SETUP > CALIBRATE menu, enter the final values for C
v
and Q
0
.
12.
Turn the pump on in the TEST > PUMP menu again and verify that the flow reading from the APDA display
matches Q
s
within 1%. If not, repeat the entire flow calibration.
13.
After the flow is calibrated, use the flow adjustment knob on the rear of the APDA-371 and adjust the flow until
the display reads 17.3 LPM. This level is within the specification of the PM
10
particle separator, and will allow for
filter loading in high concentration areas. In lower concentration areas the flow can be set at 16.7 LPM.
14.
Exit the TEST menu.
Quick Flow Check and Adjustment for Metered Flow:
These steps can be used to do a quick flow check on a Metered Flow APDA with a manual valve while it is in
operation.
4.
Insert your volumetric flow standard onto the APDA inlet, and allow the APDA flow to stabilize.
5.
Record the ambient temperature, ambient pressure, and the volumetric flow from the reference.
T
a
= Ambient Temperature (Kelvin) (Kelvin = C 273)
P
a
= Barometric Pressure (mmHg)
Q
a
= Actual Volumetric Flow
6.
Convert the volumetric flow from the reference to EPA standard conditions:
Q
s
= Q
a
* (P
a
/ T
a
) * (298 / 760)
7.
Compare the reference flow (converted to STD conditions) to the APDA flow reading (also in STD conditions).
The two should match within 1%. If not, a full flow calibration should be performed.
