Model 405 nm NO
2
/NO/NO
x
Monitor Manual Rev. D
24
6.
MAINTENANCE
The Model 405 nm NO
2
/NO/NO
x
Monitor is designed to be nearly maintenance free.
Components that require routine maintenance include the ozone scrubbers on the cell
exhaust and the DewLine
TM
Nafion tubing on the cell inlet, both of which should be
changed every year, and the air pump. The pump has a rated lifetime of 15,000 hours
(~1 year and 8 months) of operation and will need to be replaced when the flow rates
can no longer be brought into range (see Section 3.2). Operation with a high
restriction on the sample inlet will reduce the lifetime of the pump. The instrument is
designed so that pump replacement is relatively easy. Other user-serviceable
components include the LED, clock battery and solenoid valves, which are easily
replaced should they fail. In addition, the inlet filter (user supplied) should be changed
as recommended by the filter manufacturer. See Section 9 of this manual for
troubleshooting information.
A wide range of Technical Notes are provided on the 2B Tech website. The complete list
with links may be found at
www.twobtech.com/downloads_tech_notes.htm
These Tech Notes are continuously updated and new ones created.
Also, please note that all 2B Tech instrument manuals are posted online at:
http://www.twobtech.com/downloads.htm
For your convenience, a Service Log, which may be printed, is provided at the end of
this manual for recording calibrations, replacement of pumps, LEDs, etc. Records of
repairs made at 2B Tech are maintained in a database at 2B Technologies as well.
That database also includes detailed information about the construction and initial
calibration of your instrument, including digital of photos of its interior.
Maintenance
Recommendation
Frequency
Section
Reference
Recalibrate instrument
At least once per year or at
4000 hours; sooner if span
and offset are large, or if
instrument undergoes major
disassembly
7
Check flow path for
contamination
Occasionally
Contact 2B Tech
if contamination
is suspected
Check NO
x
and NO
2
scrubbers,
exhaust gas O
3
scrubbers, and
DewLine
TM
Nafion tubing and
replace if needed
Every 6 months of continuous
operation (~4,000 hrs);
otherwise annually
6
Monitor flow rates and replace
pump if indicated
Nominal 15,000 hours pump
lifetime
6
