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THEORY OF OPERATION (9000), CONT.
During this cycle, the film transport mechanism, solution heating pad, film dryer, solenoid water
valve and solution temperature controls are all activated. This initial start-up feature insures
complete mixing of all chemistry in the solution trays and wets the transport rollers to help prevent
artifacts from overnight crystals or residues that may have built up. After this initial 7 minute
cycle, the machine goes into standby while continuing to heat the chemistry. The 4 1/2 minute
mode will remain the default speed and the "LOW TEMP" light will continue to flash until the
temperature reaches 81 degrees F (27.3 C). The solution temperature will maintain at 83 degress
F (28 C) for the rest of the time the machine is on. A typical warm-up time for a starting room
temperature of about 70 degrees F (21 C) is 30-40 minutes.
It is important to note that a film may be inserted at any time during the initialization cycle or before
the "LOW TEMP" light goes out. Insertion of a film always causes the system to begin a new
timing cycle. If a film is inserted while the temperature is still low, the "TIME" select button may be
used to select the 6 minute time for processing below optimal temperature.
As an added safeguard, the 9000 Control Module will
discontinue pump operation after a
period of two (2) minutes of uninterrupted film bar operation.
This would be indicated
by the "FILM PRESENT" light remaining on for more than two minutes. This serves to limit excess
chemistry consumption.
NOTE:
A panoramic film (12" or 30.5 cm) will activate the Film Sensor Bar for about 1 1/2 minutes
at the 6 minute speed.
B. Process Mode
Three process times are available to the user. When first turned ON, the processor is pro-
grammed to select the 4 1/2 minute mode which is recommended for archival quality films. The
operator has the option of using the 6 minute process time if the solutions are not up to tempera-
ture, as may be the case early in the morning immediately after system power-up. The ENDO
mode is essentially an emergency mode and may be used if a readable but damp film is all that is
required during an endodontic procedure.
The processing mode is initiated simply by insertion of film into one or any combination of the four
film guides located along the input slot on the front of the processor. Four film sensors detect the
presence of UNPROCESSED film and begin the processing cycle. The sensors will not respond
to the presence of developed film, either clear or dark. The "PROCESS" light will illuminate
immediately and stay illuminated until the processing cycle is automatically terminated. The
processing time is determined by the "TIME" selection staus; i.e. ENDO (factory set at 2 minutes),
4 1/2 minutes, or 6 minutes. These three times are the processing times as measured from a film's
leading edge into the processor to the leading edge out of the processor. The process cycle
times of 7 minutes (for 4 1/2 and 6) and 3 1/2 minutes (for ENDO) allow sufficient time for all films
to exit the machine before it goes back into standby mode.
C. Standby Mode
In the Standby Mode, only one subsystem is activated. The solution temperature control system
maintains the chemistry temperature at 83 degrees F (28 C). The drive mechanism, drying
system and washing system are inactive to save energy and wear.
In the Standby Mode, the default processing time indicated is normally "4 1/2". Pressing the "TIME"
select button will change the processing time sequentially.
The "LOW TEMP" is a warning light. It may be off or flashing. It cannot be on continuously. It
reflects the status of the chemistry temperature. Below 81 degrees F (27.3 C), the light will flash
to alert the operator that the chemistry is below the minimum optimal operating temperature. The
actual chemistry temperature is factory-set to be 83 degrees F (28 C) + or - 1 degree. The
processor location or darkroom area should be properly vented so that ambient temperatures are
not above 80 degrees F (26.8 C).
