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Automatic calibration (autocal) – Teledyne 9110E - Nitrogen Oxides Analyzer User Manual

Page 140

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Calibration Procedures

Model 9110E Instruction Manual

126

M9110E Rev B

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.