15
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The SELECT button is a selection switch to choose the signal displayed on the LED
display meter. You can cycle up or down through the display using either the up button
or the down button.
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The ZERO button is an electronic zeroing adjustment control for offsetting the IP and the
LS signals only. DP, RI and LS are strictly baseline signals, that is, measurements are
made in the computer after subtracting the baseline. Zeroing these signals is primarily a
matter of convenience or visual reference. On the other hand, the IP signal is read by
the computer as an absolute pressure, so
it is critical that the IP signal be zeroed only
when the flow is off
.
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The TRIGGER button can be used to start an acquisition with a manual injector.
Remember to connect a contact closure signal cable output to the VAC terminal strip if
using an auto-sampler.
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The LASER button turns the power on to the laser diode. When this button is depressed
for the first time, it illuminates, indicating that the power is on. The power to the laser
diode is turned off by depressing this button a second time. The light will go off
indicating that the power is off to the laser diode.
On the right is another bank of lights, which indicates the status of operation: LASER,
IDLE, ACQUIRE, ZERO, VAPOR and SERIAL I/O:
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The LASER light indicates whether or not the power to the laser diode is on. It is
recommended that this switch be left ON at all times since a warm-up period is
required for the LASER source to become stable. NOTE: The laser operates in a
constant optical power output mode. This is not a pulsed laser unit.
•
When the IDLE indicator light is illuminated, the instrument is ready to communicate
to the host computer. This light also serves as an indicator light for the self
diagnostic routine during the power up routine. At unit power up, this LED is off until
self diagnosis is completed. Should the unit fail self diagnosis, the LED will not be
properly set.
Note: An improper set may be indicated by either none or several of the LEDS being lit.
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When the ACQUIRE indicator light is illuminated, the instrument is in the process of
acquiring data from the analog inputs. This diode will turn off after each runtime
cycle.
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The ZERO indicator light is only illuminated when either the RALS, LALS, or IP
signal is selected and the ZERO switch is pushed.
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The VAPOR light will only illuminate when the vapor sensor is activated by a leak in
the detector module. This will also shut off the solvent delivery system if a shut off
cable is attached to the terminal strip on the back of the detector.
The connector is
polarity sensitive! Pin #1 must be connected to the pump stop and pin #2
connects to pump ground.
•
When the SERIAL I/O light is on serial data is being received from the computer.
