Covidien Force FX, Service Manual

Page: 139 / 246

Calibrating the Generator
Setup, T
ests, and Adjustment
Force FX Electrosurgical Generator C Service Manual
5-31
c.
On the Power Supply/RF board, adjust potentiometer R96 for maximum amplitude
of the voltage waveform across the Patient Return Electrode receptacle pins. The
frequency of this waveform should be approximately 82 kHz.
d.
Remove the oscilloscope.
e.
Install the cover by positioning it above the chassis and sliding it down. Install the
five screws that secure the cover to the chassis.
3.
Open circuit the REM connection. Press the Coag up arrow (

) button once. Verify
that 10 appears in the Coag display.
4.
Connect the resistor substitution box across the two terminals in the Patient Return
Electrode receptacle using a modified REM plug or two test cables.
5.
Set the resistor substitution box to 10 Ω. Press the Coag up arrow (

) button once.
Verify that 70 appears in the Coag display
.
6.
Set the resistor substitution box to 70 Ω. Press the Coag up arrow (

) button once.
Verify that 135 appears in the Coag display.
7.
Set the resistor substitution box to 135 Ω.
8.
To save the REM calibration values and go to the next calibration step, press the
Bipolar up arrow (

) button.
Next, check the current sense gain factor as described in
Check and Adjust the Current
Sense Gain Factor.
Checking and Adjusting the Current Sense Gain
Equipment required
• Two short test cables (less than 24" [61 cm] long) with banana plugs
• Current transformer (such as the Pearson Model 411 or equivalent)
• True RMS voltmeter (such as the Fluke 8920 or equivalent)
• 10
Ω
noninductive power resistor (such as the Dale NH-250)
• Bipolar footswitch and monopolar footswitch
Precaution
To avoid inadvertent coupling and/or shunting of RF currents around the resistor elements, keep
the resistors at least 4" (10.2 cm) away from any metal surface including tabletops and other
resistors. This is especially true if several resistors are connected in series or parallel to obtain a
specified value. Do not allow the resistor bodies to touch each other.
Notice
Do not activate the generator with any load resistor higher than 10
Ω
while calibrating the
current sense gain. Otherwise, product damage will result.
Do not adjust the current sense gain while the generator is activated.