ULTRATHERM 908i
20
gbo Medizintechnik AG 2004
Version 1.2
4.7. Check of generator frequency and pulse parameters
4.7.1. Generator frequency
•
Connect the test aerial to output X004 and X005.
•
Connect the frequency meter to the (-40)-dB measurement output of the test aerial.
•
Set the „
DIPLODE
“ applicator, „CW“ mode and treatment time.
•
Adjust the power, wait for the tuning run.
•
Determine the transmitter frequency (f
setpoint
= 27.11 Mhz to 27.13 Mhz).
•
Turn the power selector to „0“.
•
By way of substitution and with the above adjustments, the generator frequency can be
measured with a capacitor of 1 pF/400 V connected in series to socket X004/X005 in the no-
load operation.
4.7.2. Pulsed operation of „70 Hz“
•
Connect the oscilloscope to the (-40)-dB measurement output of the test aerial.
•
Select the „70 Hz“ pulsed mode and the treatment time.
•
Select the output power and wait for the tuning run.
•
Measure the pulse duration (t
p/setpoint
= 1.8 ms to 2.2 ms) and frequency (f
setpoint
= 65 Hz to 75
Hz) by means of the oscilloscope.
•
Set the power selector to „0“.
•
The pulse duration can also be determined by means of the oscilloscope at the precision resistor
of 50
Ω
.
4.7.3. Pulsed operation of „350 Hz“
•
Select the „350 Hz“ pulsed mode and proceed according to clause 4.7.2.
•
Measure the pulse duration (t
p/setpoint
= 350 µs to 450 µs) and frequency (f
setpoint
= 325 Hz to 375
Hz) by means of the oscillossope.
•
Set the power selector to „0“.
4.8. Check of the power output
4.8.1. Coil applicator
•
Connect the test aerial including the thermal power meter to X004/X005.
•
Instead of test aerial and thermal power meter the precision resistor of 50
Ω
, multimeter and
oscilloscope can be used. However, with the pulsed modes now the power can only be
