How Fid Units Are Displayed In Agilent Data Systems And On The Gc; To Light The Fid Flame; To Extinguish The Fid Flame; Fid Automatic Reignition (Lit Offset) - Agilent Technologies 7820A Advanced User's Manual

5
Detectors

How FID units are displayed in Agilent data systems and on the GC

Table 11 Unit conversions
Data system Height units
Agilent data system 1 pA
†
SIGRange 0 1 x 10
SIGRange 5 3.2 x 10
‡
Analog 1V 1.25 x 10
* Noise is recommended maximum when determining MDL.
† SIGRange used with 3393 and 3396 integrators.
‡ Analog 1V is an approximate value.

To light the FID flame

To extinguish the FID flame

FID automatic reignition (Lit offset)

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The GC displays the FID signal in picoamperes (pA). The
following table lists how different data systems convert the
display units to reporting units.
LSV (height units)
-4
1.3 x10
-4 -4
pA 1.3 x 10
-3 -3
pA 4.2 x 10
-4
pA device dependent
Press [Front Det] or [Back Det], scroll to Flame, then press
[On/Yes].
Press [Front Det] or [Back Det], scroll to Flame, then press
[Off/No].
Lit offset is the expected minimum difference between the FID
output with the flame lit and the output with the flame off. The
GC checks this value during runs and when loading a method.
During a run, if the output falls below the Lit offset value, the FID
will attempt to reignite three times. If after the third attempt
the output does not increase by at least this value, the detector
shuts down all functions except temperature and makeup gas
flow.
When loading a method that includes a Flame On setting, the GC
performs a similar check. If the detector output is less than the
Lit offset, it will attempt reignition after reaching method
setpoints.
Area units
pA 1 pA-sec
-4
pA 1 x 10 pA
-3
pA 3.2 x 10 pA
-4
1.25 x 10 pA
*
Noise (ASTM)
0.038 pA
0.038 pA
0.038 pA
0.038 pA
Advanced User Guide