Planmeca Proline CC, Техническое руководство

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Chapter F - PREVENTIVE MAINTENANCE
F-2 Planmeca Proline CC panoramic x-ray
Technical Manual
2 PREVENTIVE MAINTENANCE CHECKS
2.1 Electrical checks
Annually or after every 10 000 exposures whichever appears first the electrical exposure param-
eters of the Planmeca Proline CC Panoramic X-ray should be checked in order to maintain the
initially accurate operation of the equipment despite of the possible long term component value
alterations.
There are no adjustments in the equipment because of its’ self-calibrating microprocessor based
operation and therefore no actual parameter trimming of the kV, mA and exposure time can be
done.If one of the parameters to be checked by this periodical preventive maintenance proce-
dure is found to be beyond the limit values allowed, the corresponding electrical circuit board is to
be changed in whole and sent back to the factory for recalibration that is done by replacing the
faulty component.
The parameters to be checked are the following:
Before exposure:
• kV measurement circuit impedance
mA measurement circuit impedance
During exposure:
• kV value
• mA value
• exposure time
In order to perform the calibration measurements the x-ray equipment must be powered off and
the rotating arm bottom cover is to be removed. The generator processor board connectors P2
and P13 are disconnected from their connectors and the PM 2002 CC Panoramic X-ray Calibra-
tion unit (order No. 50980) is connected in between these connectors. Please, be certain that the
calibration unit is connected to both the cable end connectors and to the generator processor
board connectors.
Before powering on the x-ray equipment the circuit impedance measurements should be per-
formed in order to verify the condition of the measurement resistors in the tube head and the
operational amplifier input resistors on the generator processor board.
Because the calibration unit is battery operated first put it in the BATT mode and check that the
battery voltage is above 8 V. Note that the battery check loads the battery and should therefore
be done shortly to avoid unnecessary battery discharge.
kV measurement circuit impedance measurement
Select for kV measurement and resistor mode and read the calibration unit display.
Acceptable value is from 16.20 kohms to 16.80 kohms.
If the value is not within the limits disconnect the calibration unit from the generator processor
board and make a new measurement to measure the tube head resistor only.
Acceptable value is from 17.70 kohms to 18.30 kohms.
If this result was within the limits the generator processor must be replaced. If this was not within
the limits the tube head must be replaced.