Teledyne 9110E - Nitrogen Oxides Analyzer - Manual (Page 141)

Model 9110E Instruction Manual Calibration Procedures
M9110E Rev B 127
NOTE
The CALIBRATE attribute (formerly called “dynamic calibration”) must always be
set to OFF for analyzers used in US EPA controlled applications that have IZS
option installed.
Calibration of instruments used in US EPA related applications should only be
performed using external sources of zero air and span gas with an accuracy
traceable to EPA or NIST standards and supplied through the analyzer’s
sample port (Section 7.2).
The following example sets sequence #2 to carry out a zero-span calibration every other
day starting at 14:00 on 01 January, 2003, lasting 30 minutes (15 for zero and 15 for
span). This sequence will start 30 minutes later each day.
Table 7-4: Example Auto-Cal Sequence
Mode and Attribute Value Comment
Sequence 2 Define sequence #2
Mode ZERO-SPAN Select zero and span mode
Timer Enable ON Enable the timer
Starting Date 01-JAN-03 Start on or after 01 January 2003
Starting Time 14:00 First sequence starts at 14:00 (24-hour clock format)
Delta Days 2 Repeat this sequence every 2 days
Delta Time 00:30
Repeat sequence 30 minutes later each time
(every 2 days and 30 minutes)
Duration 15.0
Each sequence step will last 15 minutes (total of 30
minutes when using zero-span mode)
Calibrate ON
The instrument will recalculate the slope and offset values
for the NO and NOX channel at the end of the AutoCal
sequence.
Please note the following suggestions for programming the AutoCal feature.
• The programmed Starting Time must be 5 minutes later than the real time clock
(Section 6.4.3).
• Avoid setting two or more sequences at the same time of the day. Any new
sequence which is initiated from a timer, the COM ports, or the contact closures will
override any sequence in progress. Note that two sequences with different daily
increments may eventually overlap.
• If at any time an illegal entry is selected, (for example: Delta Days > 366) the ENTR
key will disappear from the display.
• With CALIBRATE turned on, the state of the internal setup variables
DYN_SPAN and DYN_ZERO is set to ON and the instrument will reset the slope
and offset values for the NO and NO
X
response each time the AutoCal program runs.
This continuous re-adjustment of calibration parameters can often mask subtle fault
conditions in the analyzer. It is recommended that, if CALIBRATE is enabled, the
analyzer’s test functions, slope and offset values be checked frequently to assure
high quality and accurate data from the instrument.
To program the sample sequence shown above, follow this flow chart: