Agilent Technologies G3375A Instruction Manual

This section reviews the procedure for installing a single-channel analog
input board (AIB) on an Agilent 6850 Gas Chromatograph (hereafter called
the GC.) With the analog board installed, you can connect nonAgilent
detectors with 1 V of analog output to the GC.
This kit contains:
Description Quantity Part number
Grommet 10400-0914
Screw, M3 × 0.5, 12-mm long, pan head 10515-1084
Torx™screw, M4 × 18-mm long 20515-3034
Screw, M4 × 0.7, 12-mm long 20515-2496
Analog signal cable, general purpose, 6 pins 1G1530-60560
Analog input board 1G1556-60015
Detector PCB bracket 1G2397-00020
Insulation detector blank 1G1530-00660
MS detector plate 1G2630-20980
Installing a Single-Channel
Agilent 6850 Series II Network GC System
Analog Input Board on a 6850 GC
Accessory G3375A

2
Installing a Single-Channel Analog Input Board on a 6850 GC
Required tools
• Electrostatic protection such as grounded wrist strap
(part no. 9300-0969 [large] or part no. 9300-0970 [small])
• T-20 Torx screwdriver
• Small, flat-bladed screwdriver
• 1/8-inch drill bit and drill
Overview
Caution Before starting, review the safety information listed at the end of this
document.
1. Prepare the GC.
2. Remove the lid top cover.
3. Remove the existing detector and flow manifold.
4. Raise the lid to the service position.
5. Remove existing detector PC board.
6. Position the analog cable.
7. Install the AIB.
8. Install the insulation detector blank and detector plate.
9. Connect the analog signal cable to your nonAgilent detector.
10. Restore the GC to operating condition.

Installing a Single-Channel Analog Input Board on a 6850 GC
3
Prepare the GC
1. Load the service method or set all GC temperatures to ambient/35 °C.
2. Allow time for all heated zones to cool.
3. Turn off the GC and unplug the power cord.
4. If you have an injector installed, set it aside.
Remove the lid top cover
Remove T-20 Torx
screws (8 places)
Remove detector
cover, if desired
Remove vent tubing,
if present

4
Installing a Single-Channel Analog Input Board on a 6850 GC
Remove the existing detector and flow manifold
1. On the top of the lid, loosen the connector cover plate screws and
remove the plate.
2. Disconnect the gas fittings. The figure shows the µECD manifold; the
other manifolds are similar but vary in the number of gas connections.
3. Trace the ribbon cable from the flow manifold and disconnect it from
the harness.
4. Remove the three manifold mounting screws.
5. Remove the screws holding the detector assembly in place. You will
need a new top cover.
FID (flame ionization detector) – Remove four mounting screws.
Flow manifold
( µ ECD shown)
Gas fittings
Cover plate
screws (4)
Manifold mounting
screws
Mounting screws

Installing a Single-Channel Analog Input Board on a 6850 GC
5
TCD (thermal conductivity detector) – Remove two mounting screws.
µECD (micro cell electron capture detector) - Remove four mounting
screws.
FPD (flame photometric detector) - Remove four mounting screws. You
will need a new top cover.
6. Lift the detector and flow manifold out of the lid as a unit.
Mounting screws
Mounting screws
Two mounting
Two mounting screws
screws

6
Installing a Single-Channel Analog Input Board on a 6850 GC
WARNING The fibrous insulation material can cause irritation to the skin, eyes, and
mucous membranes. Always wear gloves when working with the insulation.
If the insulation is flaky/crumbly, wear protective eye wear and a respirator.
7. Remove any insulation that may be in the hole under the detector.
Raise the lid to the service position
1. Open the lid. Locate the counterbalance cam in the left rear corner
under the lid. Loosen the screw on the right side of the cam. This allows
the stop plate to drop down.
2. Raise the lid until it is stopped by the safety cable.
3. Raise the stop plate and tighten the screw to lock the lid in the upright
service position.
WARNING The lid is heavy. Always lock the lid when it is in the service position.
Stop plate (raised)
Counterbalance cam
Lid in service position

Installing a Single-Channel Analog Input Board on a 6850 GC
7
Remove existing detector PC board
Since there is room for only one detector on the 6850 GC, you must remove
any existing detector PC board before installing the AIB.
1. Loosen the two bottom screws on the detector electronics cover.
Caution Board compo n ents can be d amaged by stat ic electric ity; use a prope rly
grounded static control wrist strap before gaining access to the
detector electronics area and when handling the boards and any of
the cables connecting to the boards.
2. Remove the top screw on the cover.
3. Lift and remove the detector electronics cover.
Remove screw
Detector
Loosen screws
electronics
cover

8
Installing a Single-Channel Analog Input Board on a 6850 GC
4. Prepare the detector board for removal.
a. For small boards, such as the µECD shown below, remove the M3
screw that secures the detector board to the printed circuit board
(PCB) bracket.
M3 screw securing
board to bracket
Detector PCB bracket
Detector board
(µECD shown)
A/D converter board

Installing a Single-Channel Analog Input Board on a 6850 GC
9
b. For large boards, such as the FPD board shown below, remove the
detector PCB bracket holding the detector board in place.
Detector board
Detector PCB bracket
A/D converter board
(FPD shown)
mounting screw

10
Installing a Single-Channel Analog Input Board on a 6850 GC
5. Unplug and remove the existing detector board from the A/D converter
board. An FPD board is shown below. Other detector boards connect
similarly.
6. Disconnect and remove all cables from the old detector board.
All detectors – Disconnect the ribbon cable. The ribbon cable connector
will not pass through the rubber grommet in the hole. Use a small
screwdriver to push the grommet to the top of the lid; the cables will
now fit through the hole. Reinstall the grommet in the lid for later use
after you have removed the ribbon cable.
A/D converter board/
detector board connection

Installing a Single-Channel Analog Input Board on a 6850 GC
11
FPD, FID – Unplug the ignitor cable. Pass all cables through the hole to
the top side of the lid. The FID PC board is shown below.
TCD – Unplug the two-wire switching valve cable at the connector. To
release the PRT and filament wires, press down on the orange tabs. Pass
the disconnected wires through the hole to the top side of the lid.
Ribbon cable connector
Ignitor cable connector
Switching valve
PRT wires Filament wires
cable connector

12
Installing a Single-Channel Analog Input Board on a 6850 GC
7. If you have a TCD or FPD detector PCB bracket installed, remove the
existing detector PCB bracket.
Bracket for TCD
or FPD removed

Installing a Single-Channel Analog Input Board on a 6850 GC
13
Position the analog cable
1. Using a small screwdriver, install the grommet into the circular opening
in the top of the lid.
2. Route the spade lug end of the analog cable from the circular hole (with
grommet installed) underneath the lid thru the top of the lid. Pass the
analog cable through the opening at the back of the lid. See the figure
below.
Caution Take caution when routing the spade lug ends of the analog cable through
the openings in the lid of the GC. To avoid possible damage to the cable,
make sure to pass the spade lug ends through each opening before pulling
the rest of the cable through.
Cable routed through
lid opening (grommet
Cable routed through
back of lid
shown)

14
Installing a Single-Channel Analog Input Board on a 6850 GC
Install the AIB
Caution Board components can be damaged by static electricity; use a properly
grounded static control wrist strap when handling the board.
1. Install the new detector PCB bracket using the two 12-mm long M4
screws. Position the PCB bracket according to the figure below.
2. Remove the AIB from its static control bag.
3. Make certain switches 1 and 2 are in the ON position. See the figure
below.
4. Plug the AIB into the A/D converter board and secure it to the detector
PCB bracket using the M3 screw.
Bracket positioned properly
Switches 0 and 3 are
in OFF position;
switches 1 and 2 are
in ON position.
On Off

Installing a Single-Channel Analog Input Board on a 6850 GC
15
5. Connect the analog signal cable to the top of the AIB.
Note The AIB cable may be shipped with the black ferrite core positioned right at
the end of the cable, secured there with a tie wrap. If necessary, remove the
tie wrap and adjust the ferrite core position to allow the bending of the AIB
cable, as shown in the figure above.
Analog cable connected
M3 (T-20) screw
AIB
Detector PCB bracket
A/D Converter board

16
Installing a Single-Channel Analog Input Board on a 6850 GC
Install the insulation blank and detector plate
The 6850 lid is counterbalanced for the weight of installed components,
namely GC detectors. Without a detector installed, the lid will open too
quickly, posing a hazard to the user and potential damage to the GC. To
compensate for the counterbalanced lid and to protect exposed wiring,
install the detector plate and insulation blank as described below.
1. Install the circular insulation blank in place of the detector that you just
removed. See the figure below.
Insulation blank

Installing a Single-Channel Analog Input Board on a 6850 GC
17
2. Use two 18-mm long M4 screws to install the detector plate over the
insulation blank, as shown in the figure below.
Detector plate
Screws

18
Installing a Single-Channel Analog Input Board on a 6850 GC
Connect the analog signal cable to your nonAgilent detector
Connect the cable to your nonAgilent detector. The table below displays the
cable pinouts. The red, brown, and blue leads are not used and can be cut
off, if desired.
Restore the GC to operating condition
1. Install the detector electronics cover and tighten all three screws.
2. Lower the stop plate on the lid cam. Pull the lid forward until the cam
follower rests on the curved surface of the cam. Raise the stop plate
behind the cam follower and tighten the screw.
3. Close the lid. Be sure that the folded gas lines do not interfere with it.
4. Install the lid top cover.
5. Restore power.
Connector 1 Signal name Connector 2
Quick Disconnects
1No connection Brown
21 V (–) White
3No connection Red
41 V (+) Black
6No connection Blue
Shell Ground Orange
12
34
56
1
2
G1530-60560

Installing a Single-Channel Analog Input Board on a 6850 GC
19

©Agilent Technologies, Inc. 2005
All Rights Reserved. Reproduction, adaptation, or translation without
permission is prohibited, except as allowed under the copyright laws.
Part number G3375-90010
First Edition, April 2005
Printed in USA
Agilent Technologies, Inc.
2850 Centerville Road
Wilmington, DE 19808-1610
Safety Symbols
Warnings in the manual or on the instrument must be observed
during all phases of operation, service, and repair of this instrument.
Failure to comply with these precautions violates safety standards of
design and the intended use of the instrument. Agilent Technologies
assumes no liability for the customer’s failure to comply with these
requirements.
Acknowledgements
Torx® is a trademark of Textron, Inc.
In the manual
A warning calls attention to a condition or possible situation that
could cause injury to the user.
A caution calls attention to a condition or possible situation that
could damage or destroy the product or the user’s work.
On the instrument
See accompanying instructions for more information.
Indicates a hot surface.
Indicates hazardous voltages.
Indicates earth (ground) terminal.
Indicates explosion hazard.
Indicates radioactivity hazard.
Indicates electrostatic discharge hazard.
Pinch hazard.