HA243821
Issue 5 Mar 98
Section 6
Page 6 - 5
MODEL 346 INSTALLATION AND OPERATION MANUAL
6.3 CALIBRATION
The instrument calibration function permits:
1. The calibration of input channels, using precision signal standards.
2. Calibration of the thermocouple cold junction compernsation using a thermocouple at a known temperature,
or a precision thermocouple simulator.
3. Alignment of pens with the chart.
4. Determination of which software features are installed in the recorder.
Note...Calibration of RTDs sets only the excitation current for the resistance device. The actual measuring
accuracy depends on the millivolt gain span in use. Thus, to ensure maximum RTD accuracy, all millivolt
ranges should first be calibrated.
6.3.1 CALIBRATION PAGES
Change Cal?
No
This is the default selection. The up/down arrow keys are used to change the selection to one of the following:
1. Annotator carriage. The ENTER key is used to start alignment of the annotator pen with the chart. 2. Inut
channel. The ENTER key is operated to gain entry to the channel calibration menus.
3. CJ sensor. The ENTER key is used to start calibration of the cold junction sensor.
4. Factory Cal. Restores factory calibration.
5. Servo pen. The ENTER key is used to start calibration of the pen tips relative to the chart.
6. View options. Operation of the ENTER key causes the options display to appear.
7. Retransmission. Operation of the ENTER key calibrates the output channel.
PRINTHEAD
Change Cal?
Ann. Carriage
Operation of the ENTER key calls the display below, and moves the printhead to a position just beyond chart
zero. By opening the display and operating the side arrow, the trace can be moved to coincide with the chart
zero grid line. Should a mistake be made, and the adjustment go too far, operation of the CLEAR key causes
the printhead to return to its initial position to the left of chart zero.
Set Carr. Left
’C’ avoids change
Once the adjustment is successfully accomplished, operation of the ENTER key saves the new alignment. To
exit the carriage alignment menu, the CLEAR key is operated. Otherwise the page scroll key is operated to call
the display below, and the printhead moves to a position just to the left of chart full scale. With the display
open, the trace can be aligned with the chart full scale grid line. Should a mistake be made, and the adjust-
ment go too far, operation of the CLEAR key will reset the printhead position to the left of the full scale line.
Set Carr right
‘C’ avoids change
Once the adjustment has been completed, operation of the ENTER key saves the new alignment. To exit the
carriage alignment menu, the CLEAR or Page scroll key is operated to return to the ‘Change Cal?’ display.
