Teledyne 9110T Automatic ZERO/SPAN CAL/CHECK Autocal, Autocal Modes, Mode Name Action, Disabled

Model 9110TH NOx Analyzer Calibration Procedures

9.4.3.3. Use of Zero/Span Valve with Remote Contact Closure

Contact closures for controlling calibration and calibration checks are located on the rear panel CONTROL IN connector. Instructions for setup and use of these contacts are found in Section 3.3.1.6.

When the contacts are closed for at least 5 seconds, the instrument switches into zero, low span or high span mode and the internal zero/span valves will be automatically switched to the appropriate configuration.

∙The remote calibration contact closures may be activated in any order.

∙It is recommended that contact closures remain closed for at least 10 minutes to establish a reliable reading.

∙The instrument will stay in the selected mode for as long as the contacts remain closed.

If contact closures are being used in conjunction with the analyzer’s AutoCal (see Section 9.5) feature and the AutoCal attribute “CALIBRATE” is enabled, the 9110T will not re-calibrate the analyzer UNTIL when the contact is opened. At this point, the new calibration values will be recorded before the instrument returns to SAMPLE mode.

If the AutoCal attribute “CALIBRATE” is disabled, the instrument will return to SAMPLE mode, leaving the instrument’s internal calibration variables unchanged.

9.5. AUTOMATIC ZERO/SPAN CAL/CHECK (AUTOCAL)

The AutoCal system allows unattended periodic operation of the ZERO/SPAN valve options by using the 9110T’s internal time of day clock. AutoCal operates by executing SEQUENCES programmed by the user to initiate the various calibration modes of the analyzer and 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 9-2: AUTOCAL Modes
MODE NAME	ACTION
DISABLED	Disables the Sequence.
ZERO	Causes the Sequence to perform a Zero calibration/check.
ZERO-SPAN	Causes the Sequence to perform a Zero point
	calibration/check followed by a Span point
	calibration/check.
SPAN	Causes the Sequence to perform a Span concentration
	calibration/check only.

Teledyne Analytical Instruments 213