Model 405 nm NO
2
/NO/NO
x
Monitor Manual Rev. D
10
3.8.
Data Averaging and Data Logging
When first turned on, the instrument will start making measurements at a rate of once
every 5 s (unless a different averaging time was previously chosen; see Section 4.5).
Internally generated data may be logged in the internal data logger. Up to 8,192 data
lines containing log number, NO
2
, NO, NO
x
, NO
2_zero
, NO
_zero
, Cell Temperature, Cell
Pressure, Cell Volumetric Flow Rate, Ozone Volumetric Flow Rate, Sample
Photodiode Voltage, O
3
Generator Photodiode Voltage, Heated Scrubber
Temperature, Date, Time, and Status may be stored in internal memory. Averaging
times of 5 s, 1 min, 5 min and 1 hr may be selected from the menu, thereby allowing
the instrument to operate for 1.4 days, 5.7 days, 1.0 months and 0.94 years,
respectively, before filling the memory.
3.9. Summary of Operating Recommendations
The following table gives a brief summary of operating recommendations mentioned in
this manual.
Operating Recommendation
Frequency
Section
Reference
Measure and adjust cell flow rate and ozone flow
rate before operating instrument (restart instrument
after adjustment of flows)
Whenever the instrument’s
location changes in altitude
3.2
Allow ~20 minutes for instrument warmup before
taking data
Each startup
3.3
Inlet tubing should be made of inert materials, such
as PTFE, PFA, FED, PVDF (do not use Tygon
®
,
polypropylene, or metal tubing)
Each use
3.4
Use a Teflon or PVDF inlet filter; test it for NO
2
and
NO loss
Each use
3.4
Vent exhaust to atmospheric pressure and out of
room or shelter
Each use
3.4; also
page 4
Check the span and zero offset; decide whether to
make use of the instrument’s Auto Zero function
Periodically
3.5, 7
Perform multipoint calibration
Annually
Any time major
disassembly of
components is performed
Any time the zero or span
checks give results
outside of the acceptable
limits
4, 7
If strong temperature fluctuations are expected,
place the instrument in a thermally insulated box
User-defined
3.4
During aircraft sampling, do not point inlet tube into
the wind
User-defined
3.4
Use adaptive filter if rapidly changing NO/NO
2
concentrations are occurring or are anticipated
User-defined
1.2
