TRANSMITTER MAINTENANCE
6.1 COLD START
A ‘COLD START’ will resets all ‘Set-up’ mode entries to their normal default values. ‘COLD START’ will show on
the display for a second prior to a microprocessor initialising sequence, which takes about seven seconds.
After a ‘COLD START’, it is necessary to set all new variables in the set-up mode, including calibration voltages and
time and date.
To initiate a ‘COLD START’ -
Turn the mains power off
Remove the ‘COLD START LINK’ (this is located on the door PCB, next to the keyboard lock switch, behind the
shield)
Turn the mains power on. The message “Cold Start......” will be displayed.
Leave the LINK off until the message “Replace c/s Link” is displayed. Replace the LINK.
The date and version number of the software will be displayed.
A ‘WARM START’, which is performed by applying power with the COLD START LINK in its place, will retain all
data previously entered in the Set-up mode.
Location of Calibration Test Points
6.2 A/D CALIBRATION
Ribbon Cable
Ribbon Cable
Reference
Reference
test
oints.
common
Door
1630-1 PC
40 Wa
16 Wa
The Analyzer maintains its accuracy over a very long by continuously checking itself against internal stabilised
references. The only calibration required is to set the actual values of these references into battery backed memory.
The Analyzer will read these references every minute and update its zero and span correction factors. See Section 5.5.6
to 9.
These references should be checked every 12 months. An AUTOCAL of the analog output section should always be
performed if these references are altered. See Section 6.3.
6.3 D/A (4-20mA output channels) Calibration
If a ‘COLD START’ is performed (Section 6.1), then the D/A section of the Analyzer will be automatically calibrated.
The D/A section should be manually re-calibrated after the instrument has been switched on for 30 minutes and
stabilised. This is achieved by pressing the ‘AUTO CAL’ button while the Analyzer is in the set-up mode. This button
should be pressed annually, or if the reference voltages in the set-up menu are altered. Refer to Section 5.5, items 6, 7,
8, 9, 16 and 17 to re-calibrate the D/A converter and isolated output section. An ‘AUTO CAL’ will be performed after
pressing the button. The transmitter outputs will fall to 0 mA for about a second.
6.4 PUMP REPLACEMENT
Page 42 Teledyne Analytical Instruments 9070 Oxygen Analyzer
