Teledyne 9110EH - Nitrogen Oxides Analyzer - Manual (Page 140)

Calibration Procedures Model 9110EH Instruction Manual
7.8. Automatic Calibration (AutoCal)
The AutoCal feature allows unattended, periodic operation of the zero/span valve options by
using the analyzer’s internal time of day clock. The AutoCal feature is only available on the
front panel menu (ACAL) if either the zero/span valve or the IZS option is installed.
AutoCal operates by executing user-defined sequences to initiate the various calibration
modes of the analyzer and to open and close valves appropriately. It is possible to program
and run up to three separate sequences (SEQ1, SEQ2 and SEQ3). Each sequence can
operate in one of three modes or be disabled (Table 7-2).
Table 7-2: AutoCal Modes
Mode Action
Disabled Disables the sequence
Zero Causes the sequence to perform a zero calibration or check
Zero-Span
Causes the sequence to perform a zero calibration or check followed by
a span concentration calibration or check
Span
Causes the sequence to perform a span concentration calibration or
check
Each mode has seven parameters that control operational details of the sequence
(Table 7-3).
Table 7-3: AutoCal Attribute Setup Parameters
Parameter Action
Timer Enabled Turns on the sequence timer
Starting Date Sequence will operate on Starting Date
Starting Time Sequence will operate at Starting Time
Delta Days Number of days between each sequence trigger. If set to 7, for example, the
AutoCal feature will be enabled once every week on the same day.
Delta Time Incremental delay on each delta day that the sequence starts. If set to 0, the
sequence will start at the same time each day. Delta Time is added to Delta Days
for the total time between cycles.
This parameter prevents the analyzer from being calibrated at the same daytime of
each calibration day and prevents a lack of data for one particular daytime on the
days of calibration.
Duration Duration of the each sequence step in minutes. This parameter needs to be set
such that there is enough time for the concentration signal to stabilize. The STABIL
parameter shows if the analyzer response is stable at the end of the calibration.
This parameter is logged with calibration values in the iDAS.
Calibrate Enable to do a true, dynamic zero or span calibration; disable to do a calibration
check only. This setting must be OFF for analyzers used in US EPA applications and
with IZS option installed.
RANGE TO CAL LOW calibrates the low range, HIGH calibrates the high range. Applies only to auto
and remote range modes; this property is not available in single and independent
range modes.
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