Output Power Calibration Procedure - ConMed Sabre 2400 Operators & Service Manual

• It is only necessary to activate the unit for the
selected point to be considered calibrated. No
actual adjustment is required, but the output cur-
rent should still be measured and verified against
the target value. This eliminates unnecessary
"tweaking" if a point is adjusted correctly already.

4.6.3 Output Power Calibration Procedure

Note: This procedure lists a complete power
calibration. It is possible to go directly to bipolar
mode power calibration ("bP" in the display) if
desired by selecting that mode first. In general
the complete calibration should be done. This is
because whatever changed an output in one mode
requiring recalibration will likely affect the other
mode.
1. Remove the two screws at the rear of the unit
to open the top cover.
2. Connect the output power tester to the Return
Electrode jack and one of the active monopolar
RF output jacks, depending on how one wishes
to activate the unit. If possible, set the tester for
the rated load resistance, since this will yield the
most accurate calibration results. If this resistance
is not available, the Sabre 2400 may be calibrated
using 300, 400 or 500 ohm loads.
3. Connect the power plug to a source of AC
power of the same frequency and within 1% of
the voltage specified on the nameplate.
4. Press A2SW1 (marked CAL) on the micro/
control PWB, while turning on the unit's circuit
breaker. Successful entry to CAL mode is signi-
fied by all segments of the display lighting.
5. Press "SEL ". The unit will then momentarily
display "CAL " and proceed to display "C-C" in
the Cut Power Window, either 300,400,or 500 in
the Coag Power Window, and "A" or "P" in the
Bipolar Power Window. Use the Power Increase/
Decrease to set your requirements. Example:
Desired RF load is 500 ohms, and target display
in Power. Press the Coag Power Increase Key
to set "500" in the Coag Power Window, and
the Bipolar Power Increase Key to set "P" in the
Bipolar Power Window.
6. Press "SEL " to move into the actual calibration.
The Power Windows will display the target value
in amps or watts as determined above.
7. Activate the unit and use the Power Increase/
Decrease Keys next to the mode being activated
to set output to match the displayed target as
closely as possible. Deactivate when the best
match occurs.
NOTE: Heating tends to change the gain of the
power amplifier slightly, so a slow change in load
current may be noted while the unit is activated.
These errors may be minimized by allowing the
unit to cool for 15 to 20 seconds between acti-
vations. This phenomenon is not ordinarily a
problem unless the unit is far out of calibration,
requiring extended activations in order to bring it
in. In such cases, first perform a complete rough
calibration. Let the unit cool for several minutes,
then repeat the calibration. Now the activation
time necessary to close in on final adjustments
will be very brief.
8. Press the Power Increase/Decrease Key to move
the target to the next calibration point. Repeat
steps 6 & 7 for Pure, Blend and Coag until all
points are calibrated (no points are flashing).
9. When all monopolar points have been calibrat-
ed satisfactorily, pressing the "SEL " key will store
the updated values and restore the menu. The
display will show a steady "C-C" if the calibration
has been completed properly, otherwise it will be
flashing or show a HLP code.
10. Disconnect the tester from the Monopolar
outputs, and connect it to the Bipolar output
jacks. Set the tester up for the rated load of 50
ohms if possible, otherwise select 100 or 125 for
output load resistance.
11. Use the Cut Power Increase/Decrease Keys to
select "bP" in the Cut Power Window. Select the
same RF load as chosen above by using the Coag
Power Increase/Decrease Keys, and select the
target display mode as "A" for amps, or "P" for
Power in watts (in the Bipolar Power Window)
using the Bipolar Power Increase/Decrease Keys.
Press "SEL " to enter the Bipolar calibration mode.
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