PerkinElmer CLARUS 590 GC, User Manual

Page: 45 / 284

Detectors . 45
Detectors
Detector screens provide fields that allows you to control a number of parameters during a run, such as
temperature, range, and attenuation. Other active elements include a Heater Off check box to turn off the
detector and an AutoZero check box. Selecting the AutoZero check box prompts the system to zero the
signal before the run and also activates the Signal button on the Signal screen. The mV value next to the
small signal icon that displays the current signal. The read-only text provides details about configuration
settings. The following screen shows the major components that apply to all detector screens. The Gas
Flow section is only included with PPC. The subsections that describe each detector type includes details
about settings that are unique to that particular detector.
FIDW
The FIDW (Flame Ionization Detector Wide Range) uses a hydrogen and air flame to generate ions from
the combustion of an organic compound. The detector collects and measures the concentration of these
ions to determine the amount of compound in the sample. This section describes the screen components
for each type of configuration.
The Ignite button allows you to light the FID flame.
About Auto-Ignition
The PPC version of the FIDW has
flameout
detection and an
auto-ignite
feature. Flameout detection
occurs 0.5 minutes into the PRE-RUN time and it measures the user-entered baseline threshold level in
mV. If the threshold level is exceeded, the flame is considered lit, otherwise the Clarus GC detects that
the flame is out and auto-ignite automatically lights the flame before the start of a run.
With the temperature set, the air and hydrogen flows set, and auto-ignition activated by setting a positive
mV value for the flame offset, the detector attempts auto-ignition at -0.5 min. before the system
becomes ready. At this Pre-run time the status bar flashes “
Flame Ignition”
as the air flow is shut off,
hydrogen purges the detector for about 10 seconds, and the ignitor energizes for ignition followed by a
return of the air flow to the detector to sustain the flame.
Touch this button to turn
the detector heater OFF.
Dynamic text
displays the
current signal.
Selecting the
AutoZero checkbox
zeros the signal
before the run.
Touch the Ignite
button to light
the FID flame.
Temperature
setpoint.
Actual
temperature.
Indicator lights
show the gas
flow status.