INFICON 3000 Micro GC Gas Analyzer Operating Manual - Manual (Page 38)

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3000 Micro GC Operating Manual
3.3.3 Injectors
Depending on application requirements, 3000 Micro GC supports four different
types of injectors. These MEMS based injector “wafers” contain sample loops
etched into the wafer and micro-diaphragm valves used to direct sample and
carrier gas flow. The sample volume is controlled in EZ IQ by the Inject Time in
milliseconds (ms). The Injector Temperature can be set from 40-100
° C or be
turned off.
3.3.3.1 Variable Injector (Timed)
The variable injector allows the injection volume to be changed by the user. An
inject time of 0 ms results in no injection.
Valid settings are between 10-100 ms. No significant difference in inject volume is
achieved after 100 ms.
The typical setpoint is 25 ms. Values less than 10 ms may result in repeatability
issues.
The higher the setting, the more sample is injected which results in higher
sensitivity. Actual injection volumes are on the order of a few microliters (µL) of gas.
Variable injectors will show the matrix effect as the sample density varies with
compositional changes.
3.3.3.2 Variable Large Volume Injector (Timed)
Similar to the Variable Injector, the Large Volume Injector can be programmed to
inject a large volume. Variable Large Volume Injectors should only be used when
low sensitivity (1-10 ppm) is required. An Inject Time of 0 ms results in no injection.
Valid settings are between 10-400 ms. No significant difference in inject volume is
achieved after 400 ms.
Values less than 10 ms may result in repeatability issues.