Preventive Maintenance
Flame photometric detector
this indicates a leak in the system. Begin checking possible leak sources and monitor the EFS to determine when the leak has been eliminated.
Possible leak sources, in order of probability are:
1.septum
2.column fittings
3.supply line swage•typeplumbing connections
4.detector block O•ringor Vespel seals
5.other system plumbing
Caution When leak•testingthe flow system under pressure, do not exceed 210 kPa (30 psig), because higher pressures may damage the detector block window or seals.
FPD leak testing (GC without electronic flow sensor)
If a leak is suspected in an instrument without an electronic flow sensor, possible leak sources can be checked in the order listed (1 through 5) above. This can be done by capping off the detector exhaust and pressurizing the system to 140 kPa (20 psig). Then close off the supply flow and monitor the rate of pressure drop. Pressure should drop no more than 7 kPa (1 psig) per minute.
WARNING If using liquid solution to locate leaks, to avoid a potential shock hazard, place the main power switch in its off position and disconnect the main power cord. Be careful not to spill leak solution on electrical leads•especially the detector heater leads!
Note: Except when leak testing, it is best to leave the detector module at operating temperature at all times (whether the flame is lit or extinguished) to minimize thermal expansion/contraction.
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