Teledyne gfc 7000ta operation manual Automatic Zero/Span Cal/Check AutoCal, Autocal Modes

Models: gfc 7000ta

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Calibration Procedures

Model GFC7000TA Carbon Dioxide Analyzer

7.5.2. Use of Zero/Span Valves with Remote Contact Closure

Contact closures for controlling calibration are located on the rear panel CONTROL IN connector. Instructions for setup and use of these contacts are found in Section 6.15.1.2. When the contacts are closed for at least 5 seconds, the instrument switches into zero or span mode. 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 calibration is enabled, the GFC 7000TA will re-calibrate when the contact is opened, then go into SAMPLE mode. If calibration is disabled, the instrument will return to SAMPLE mode, leaving the calibration unchanged.

7.6. Automatic Zero/Span Cal/Check (AutoCal)

The AutoCal system allows unattended periodic operation of the ZERO/SPAN valve options by using the GFC 7000TA’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 3 separate sequences (SEQ1, SEQ2 and SEQ3). Each sequence can operate in one of 3 Modes, or be disabled.

 

Table 7-1: 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 and span concentration

 

calibration/check

SPAN

Causes the Sequence to perform a span concentration

 

calibration/check

For each mode there are seven parameters that control operational details of the SEQUENCE. They are:

Table 7-2: AutoCal ATTRIBUTE Setup Parameters

ATTRIBUTE NAME

ACTION

TIMER ENABLED

Turns on the Sequence timer

STARTING DATE

Sequence will operate after Starting Date

STARTING TIME

Time of day sequence will run

DELTA DAYS

Number of days to skip between each Seq. execution

DELTA TIME

Number of hours later each “Delta Days” Seq is to be run

DURATION

Number of minutes the sequence operates

CALIBRATE

Enable to do a calibration – Disable to do a cal check only

Teledyne Analytical Instruments

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Page 191
Image 191
Teledyne gfc 7000ta Automatic Zero/Span Cal/Check AutoCal, Use of Zero/Span Valves with Remote Contact Closure