NPD toFID conversion onSRI 8610C or 310CGC
The electronic parts are shown at
right:
4P4C pin telephone jack
1000ohmpot
100ohm resistor
Momentary switch
Pushbuttons
LED
note that the longer leg on the LED
is the positive Be sure to install in
the circuit boardwith the correct
orientation.
TheNPD toFID conversion kit
also includes two flow restrictor
tubes. The longer onewith red
markings is thehydrogen restric-
tor, the shorter tubewith blue
markings is theair restrictor.
The flow restrictors aremounted
inside theGC chassis directly be-
low the detector.
Replace the existingNPD flow re-
strictorswith theFID flow restric-
tors. TheFID hydrogen flow re-
strictor will deliver a flow of 20ml/
minwith theH2 pressure set to
20psi. TheFID air restrictor will
deliver a flow of 250ml/min of air
when theAir pressure is set to
5psi.
Make sure all the nuts are tight.
Leak check using the pressure
dropmethoddescribedonSRI’s
website.
Page10
