Model 202 Ozone Monitor Manual Rev. J-4
29
Wrong baud rate selected.
Make sure that the baud
rate chosen in the menu
matches the baud rate
setting of your data
acquisition program.
Required calibration
parameters are outside
the adjustable range (
9
ppbv offset and/or
9%
slope) when calibrated
using a standard ozone
source or reliable ozone
instrument.
Ozone scrubber is
contaminated.
Flow path is contaminated.
Solenoid valve is
contaminated and not
opening and closing
properly.
Air pump is not drawing
sufficient flow.
Replace ozone scrubber.
Be sure to use an inlet filter
to remove particulate
matter.
Clean flow path with
methanol following the
Cleaning Procedure (
Tech
Note 018
).
Remove solenoid valve,
rinse with methanol, dry
with zero air, and replace.
As a first check, hold your
finger over the air inlet to
determine whether air is
being drawn in. If there is
flow, measure the flow rate
by removing the bottom
cover and attaching a high
conductance flow meter to
the exit port of the pump.
Air flow should be greater
than 0.7 L/min. If flow is
lower, check for leaks. If
there are no leaks, replace
air pump.
Instrument always reads
close to zero for ozone
concentration.
Solenoid valve cable is not
properly connected to
circuit board.
Reattach solenoid valve
cable to circuit board (see
Figure 9-3).
