Extrel Max300-LG - Remaining Components in the Enclosure; Inlet Valves

Max300-LG : Description - Specifications - Installation Guide
Extrel Core Mass Spectrometers
Page 9
Detector
Two different detector options are offered. The standard detector is the faraday plate.
This component, located directly after the quadrupole, collects the signal of the ions. An
optional electron multiplier detector assembly is available for increased dynamic range. It
is recommended that the standard faraday detector be wiped off occasionally, especially
for dirty applications.
Remaining Components in the Enclosure
In addition to the vacuum system components, the controlling electronics are also
mounted in the enclosure, including the Quadrupole Controller (QC), the preamplifier
and the card cage with its modules.
Sample Stream Inlet Hardware
The pressure reduction system is necessary to adjust the incoming sample stream to
conditions suitable for introduction into the mass spectrometer. This involves reducing
the sample stream pressure to an acceptable level.
Inlet Valves
The sample selection valve, the heated transfer line, and the inlet assembly deliver the
sample stream to the instrument for analysis. The sample selection valve is used to select
the sample stream to be analyzed while the transfer line connects the output of the desired
stream to the pressure reduction system and the inlet assembly. The tee of the inlet is
used to remove excess sample and decrease inlet clearing time. A small portion of the
sample stream flows through the heated transfer line, into the inlet, and is admitted into
the mass spectrometer. A flow switch (50 cc/min) is used to monitor for loss of sample
flow at all times.
The transfer line, tee and inlet assembly can be heated to prevent condensation of stream
components as the sample is transported into the mass spectrometer. The transfer line can
heat the tubing from room temperature to 300
○
C. A heater located around the inlet heats
the assembly.
The inlet requires no regular maintenance. The size of the fused silica inlet restrictor is
dependent on the application. Particulates in the sample stream may clog the assembly
and force it to be changed.