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Below the Viscotek Corporation Logo On the lower portion of the electronics module
is a smoked plastic cover that encloses several switches and a push-button used for
operating the Model 300TDA. They include: MAIN POWER button, REFRACTOMETER
and VISCOMETER PURGE, REFRACTOMETER ZERO, as well as a DC POWER
RESET switch.
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The MAIN POWER push-button turns the AC power On/Off. This switch will disable
all electronic components including the heater circuit. This switch is always left ON
during data acquisition.
•
The REFRACTOMETER PURGE switch is used to control an electronic valve that is
used to purge the reference side of the cell with fresh solvent. Normal HPLC pump
flow-rate is required for a period of approximately 5 minutes (or until a stable Display
Meter reading is achieved) to adequately purge the Refractometer. Additionally, the
positive signal side of the Inlet Pressure transducer is purged simultaneously. This
switch must be in the OFF position for data acquisition.
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The VISCOMETER PURGE switch is used to control a pair of electronic valves that
are used to purge the two halves of the Differential Pressure transducer. Again,
normal HPLC flow is required for approximately 5 minutes (or until a stable Display
Meter reading is achieved) to adequately purge the viscometer. The negative signal
side of the Inlet Pressure transducer is continuously purged during normal operation
of the Model 300TDA.
•
The REFRACTOMETER ZERO switch is used to adjust the optical alignment of the
Refractometer signal during the initial setup and upon solvent change-over. To
make adjustments hold the switch either up or push down depending upon the
algebraic sign of the signal displayed.
NOTE: Once the zero has been obtained, do
not change or re-zero the signal while running samples. If it is necessary to re-zero
the signal, you may need to re-calibrate the RI detector. See the TriSEC 3.0
Software manual for this procedure.
•
The DC POWER RESET switch is used to reestablish serial communication between
Model 302TDA and its data station. If either power surges or signal saturation are
experienced during normal data acquisition result in an apparent “lock-up” of the data
stream it will be necessary to STOP data acquisition and use this switch to reset the
internal CPU for proper operation. Use of this switch does not effect proper
temperature control.
Located to the left hand side of the electronics module is the Oven Compartment that
contains space for up to 3 separation columns and the Model 302TDA detectors. This
compartment may be removed from its housing by loosening the two panel screws
located at the center top and bottom of the compartment front panel. A handle is
provided in the front and rear of the drawer as an aid in removal.
Note: No locking mechanism is provided for sliding the detector drawer out of the
oven chamber.
Also, HOT surfaces will be encountered upon removal
.
