Model 106-L Ozone Monitor Manual Rev. E
6
negative (black) wires correctly. Batteries and battery chargers are available
from 2B Technologies. A circuit breaker and diode are installed on the circuit
board in case of an electrical short or incorrect battery attachment. If activated,
the breaker will reset itself after a few minutes.
Lead-acid batteries are available from numerous manufacturers in a wide range
of sizes and amp-hour ratings. The larger of these, such as those for
automobiles or boats, will supply power for up to several weeks. Battery packs
in the correct voltage range may be constructed from nickel-cadmium
(rechargeable) or lithium (light weight but not rechargeable) batteries for
operation for a few hours. Battery options available through 2B Technologies
may be found on our webpage:
www.twobtech.com
.
Once turned on, the instrument will display the version number of the software
installed on the microprocessor. After a few seconds, the instrument will start
displaying readings for ozone. The first dozen readings (requiring about two
minutes) will be spurious, with large positive and negative swings due to the
rapid warmup of the lamp and electronics. Also, ozone readings may be
inaccurate during the 10-20 minutes required for the lamp, photodiode, and
internal temperature of the absorption cell to stabilize.
Inlet tubing may be attached to the ¼ inch nylon Swagelok fitting on the back of
the instrument. The inlet tubing should be made of PTFE (Teflon
), PFA, FEP ,
PVDF or some other inert material that does not destroy ozone and that does
not desorb plasticizers and other organics that can contaminate the flow path.
The length of tubing should be kept as short as possible (preferably not more
than a few feet) to minimize ozone destruction within the inlet tubing. Tygon
,
polypropylene (which may look like Teflon) and metal tubing should not be
used. FEP-lined Tygon tubing, which is used inside the instrument provides the
flexibility of Tygon with the inertness of FEP. A Teflon or PVDF inlet filter is
highly recommended to prevent internal contamination of the tubing and
absorption cell by particulate matter. The filter should be tested for ozone loss
by measuring ambient ozone with and without the filter attached. Filters and
filter holders are available through 2B Technologies.
Although the instrument compensates for temperature drift, if strong
temperature fluctuations are expected, as in vertical profiling applications using
balloons, the instrument should be placed in a thermally insulated box.
Measurement of the Zero Offset
The electronic zero of the instrument may be measured by attaching an ozone
destruction cartridge to the air inlet for a period of 5-10 minutes. For an
