Dionex CD25 Operator's Manual
CD25 CONDUCTIVITY DETECTOR
OPERATOR'S MANUAL
© 2000 Dionex Corporation
Document No. 031687
Revision 01
April 2000
©2000 by Dionex Corporation
All rights reserved worldwide.
Printed in the United States of Amer ica.
This publication is protected by federal copyright law. No part of this publication
may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or
transmitted into any human or computer language, in any form or by any means,
electronic, mechanical, magnetic, manual, or otherwise, or disclosed to third parties
without the express written permission of Dionex Corporation, 1228 Titan Way,
Sunnyvale, California 94088-3603 U.S.A.
DISCLAIMER OF WARRANTY AND LIMITED WARRANTY
THIS PUBLICATION IS PROVIDED “AS IS” WITHOUT WARRANTY OF
ANY KIND. DIONEX CORPORATION DOES NOT WARRANT,
GUARANTEE, OR MAKE ANY EXPRESS OR IMPLIED
REPRESENTATIONS REGARDING THE USE, OR THE RESULTS OF THE
USE, OF THIS PUBLICATION IN TERMS OF CORRECTNESS, ACCURACY ,
RELIABILITY, CURRENTNESS, OR OTHERWISE. FURTHER, DIONEX
CORPORATION RESERVES THE RIGHT TO REVISE THIS PUBLICATION
AND TO MAKE CHANGES FROM TIME TO TIME IN THE CONTENT
HEREINOF WITHOUT OBLIGATION OF DIONEX CORPORATION TO
NOTIFY ANY PERSON OR ORGANIZATION OF SUCH REVISION OR
CHANGES.
TRADEMARKS
Teflon® and Tefzel® are registered trademarks of E.I. duPont de Nemours & Co.
AutoSuppression™, DX-LAN™, IonSep®, MPIC™, OmniPac®, OnGuard™,
SRS®, and Self-Regenerating Suppressor® are trademarks of Dionex Corp.
PRINTING HISTORY
Revision 01, April 2000
Contents
1 • Introduction
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
1.2 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
1.2.1 Typefaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
1.2.2 Safety Messages and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
1.3 Safety Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
2 • Description
2.1 Front Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.1.1 Control Panel Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.1.2 Control Panel Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
2.2 Electronics Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
2.3 Conductivity Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12
2.4 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-15
2.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16
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2.1.3 Initial Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
2.2.1 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9
2.2.2 Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9
2.3.1 DS3 Detection Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
2.3.2 Shielded Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
2.5.1 Operating and Control Modes . . . . . . . . . . . . . . . . . . . . . . . .2-16
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CD25 Conductivity Detector
2.5.2 Local and Remote Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
2.5.3 Method Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
3 • Operation and Maintenance
3.1 Getting Ready to Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 Running Under Direct Control (Local Mode) . . . . . . . . . . . . . . . . . . . 3-2
3.3 Running Under Method Control (Local Mode) . . . . . . . . . . . . . . . . . . 3-3
3.3.1 Running a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.2 Changing the Running Method . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.3 Creating a New Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3.3.4 Editing an Existing Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.4 Optimizing Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . 3-7
3.4.1 With a DS3 and Conductivity Cell . . . . . . . . . . . . . . . . . . . . . 3-7
3.4.2 With a Shielded Conductivity Cell . . . . . . . . . . . . . . . . . . . . . 3-8
3.5 Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
4 • Troubleshooting
4.1 No Detector Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2 Low Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.3 High Detector Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.4 Noisy or Drifting Baseline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
4.5 Liquid Leaks from the DS3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.6 DS3 Temperature Inaccurate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
4.7 Conductivity Inaccurate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
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4.8 Faulty DX-LAN Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
4.9 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
5•Service
5.1 Eliminating Liquid Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
5.2 Removing Trapped Air from the Cell . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
5.3 Replacing the DS3 Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
5.4 Calibrating the Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
5.5 Replacing the Main Power Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
A • Specifications
Contents
5.6 Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.1 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.2 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.3 Display and Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
A.4 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
A.5 Conductivity Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
A.6 SRS Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
A.7 DS3 Detection Stabilizer (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
B • Installation
B.1 Facility Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
B.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
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CD25 Conductivity Detector
B.2.1 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
B.2.2 DX-L AN Interfa ce: 10BASE-T Connection s (Optional ). . . . .B-3
B.2.3 DX-LAN Interface: BNC Connections (Optional). . . . . . . . . .B-6
B.2.4 DS3 Detection Stabilizer Installation. . . . . . . . . . . . . . . . . . . .B-9
B.2.5 Shielded Conductivity Cell Installation . . . . . . . . . . . . . . . . . .B-9
B.2.6 DS3 or Shielded Cell Plumbing. . . . . . . . . . . . . . . . . . . . . . . .B-9
B.2.7 Recorder/Diagnostic Connection . . . . . . . . . . . . . . . . . . . . . .B-17
B.3 Automatic SRS Power Control (Optional) . . . . . . . . . . . . . . . . . . . . .B-18
C • User Interface
C.1 Operational Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-2
C.1.1 Menu of Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-2
iv
C.1.2 Main Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-3
C.1.3 Detail Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-4
C.1.4 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-5
C.1.5 Module Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-7
C.1.6 Analog Out Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-8
C.1.7 Time Function In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-9
C.2 Diagnostic Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-10
C.2.1 Diagnostic Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-10
C.2.2 Power-Up Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-11
C.2.3 Elapsed Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-12
C.2.4 Analog Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-13
C.2.5 DX-LAN Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-14
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C.2.6 Keyboard Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-16
C.2.7 Diagnostic Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-17
C.2.8 Leak Sensor Calibration and Status. . . . . . . . . . . . . . . . . . . . C-19
C.2.9 Signal Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-20
C.2.10 Calibrate Conductivity Cell. . . . . . . . . . . . . . . . . . . . . . . . . . C-21
D • TTL and Relay Control
D.1 TTL and Relay Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
D.2 TTL and Relay Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
D.3 TTL Input Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
D.3.1 TTL Input Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
D.3.2 TTL Input Signal Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5
Contents
E • Signal Processor Functions
F • Connector Pinouts
F.1 Recorder/Diagnostic Signal Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . F-1
F.1.1 Signal Electrical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . F-2
F.2 TTL/Relay Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-4
F.3 DS3 Connector Pinouts—SCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-5
F.4 SRS Connector Pinouts—SCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6
F.5 Conductivity Cell Connector Pinouts—SP . . . . . . . . . . . . . . . . . . . . . F-6
G • Reordering Information
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CD25 Conductivity Detector
vi
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1.1 Overview
The CD25 Conductivity Det ect or is a sensitive, accurate , and versatile ins tr ument
for detecting and quant ifying ionic analytes in liq uid and ion chromatog raphy. It is
especially useful for analytes that lack UV chromophores and cannot be
determined with adequate sensitivity by UV absorbance. Conductivity detection,
especially when combined with chemical eluent suppression, provides excellent
sensitivity and selectivity for numerous ionic species, both organic and inorganic.
The major organic analytes are carboxylic, sulfonic, and phosphonic acids; and
primary, secondary, tertiary, and quaternary amines. Inorganic analytes include
strong acid anions such as the halid es, sulfate , nitrat e, and phos phate; alkali metal
and alkaline earth cations.
The CD25 ca n be controll ed locally, from the front panel, or remotely (via th e
Dionex DX-LAN™ interface) from a host computer running PeakNet 6, Release
6.1 (or later) software.
1 • Introduction
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1-1
CD25 Conductivity Detector
1.2 About This Manual
Chapter 1
Introduction
Chapter 2
Description
Chapter 3
Operation and
Maintenance
Chapter 4
Troubleshooting
Chapter 5
Service
Appendix A
Specifications
Appendix B
Installation
Appendix C
Display Screens
Provides a brief overview of the CD25 Conductivity
Detector. Explains the meaning of safety messages and
icons in the manual and safety labels on the detector.
Describes physical aspects of the CD25, including the
front panel controls, electronics, and flow cell. Explains
the detecto r operating m odes.
Describes operating features and how to create, edit, and
run methods from the CD25 front panel. Lists routine
preventive maintenance requirements.
Lists possible causes of problems and step-by-step
procedures to isolate and elimina te th em.
Contains step-by-step instructions for routine service and
parts replacement procedures.
Lists the CD 25 specifica tions and installation site
requirements.
Describes how to install the CD25.
Illustrates and describes all operating and diagnostic
screens that can be displayed on the front panel.
1-2
Appendix D
TTL and Relay
Control
Appendix E
Signal Processor
Functions
Appendix F
Connector
Pinouts
Appendix G
Reordering
Information
Describes TTL and relay control functions. Provides
connection instructions.
Lists the functions of the Signal Processor (SP) card.
Describes the pinouts for all CD25 connectors.
Lists spare parts for the detector.
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1.2.1 Typefaces
Capitalized bold type indicates a front panel button:
Enter
Press
Uppercase bold type indicates the name of a menu or a screen, or an
on-screen entry:
1 • Introduction
to begin running the method.
Go to the
METHOD
Move the cursor to the
screen.
EDIT
field.
1.2.2 Safety Messages and Notes
This manual contains warnings and precautionary statements that can
prevent personal injury and/or damage to the CD25 when properly
followed. Safety messages appear in bold type and are accompanied by
icons, as shown below.
Indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury.
Indicates that the function or process of the instrument may be
impaired. Operation does not constitute a hazard.
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1-3
CD25 Conductivity Detector
Informational messages also appear throughout this manual. These are labeled
NOTE and are in bold type:
NOTE NOTES call attention to certain information. They alert
you to an unexpected result of an action, suggest how to
optimize instrument performance, etc.
1.3 Safety Labels
The CE and GS safety label on the CD25 attests to compliance with the following
European, EMC, and safety requirements: Council Directives 73/23/EEC and 89/
336/EEC, EN 61010-1:1993 (safety), EN 50082-1:1992 (susceptibility), and EN
55011:1991 (emissions).
The symbols below appear on the CD25 or on CD25 labels.
Alternating current
˜
Protective conductor terminal (earth ground)
Power supply is on
Power supply is off
1-4
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2.1 Front Control Panel
The control panel on the f ront door of t he CD25 contains the liquid crystal di splay
(LCD), the membrane keypad, and the actuator for the main power switch. The
electronics chassis, described in Section 2.1.3, is located behind the front door.
Power Switches
The main power switch is on a bulkhead inside the electronics chassis (in the
front, left-hand corner). The actuator for the power switch is on the front door,
below the control panel (see Figure 2.1.2). The actuator functions only when the
front door is fully closed. When the door is open, press the main power switch to
turn the CD25 on and off.
2.1.1 Control Panel Display
2 • Description
and
screen
, displays CD25 status and operating
Menu
buttons (see Figure 2-1).
option on the
MODULE SETUP
screen
The LCD, also called the
information. Fields on the sc ree n tha t ar e in reverse video (blue lette rs on
a white background) can be edited, while normal video fields are simply
informational displays.
To adjust the screen contrast, rotate the knurled knob in the recess
below the
To adjust the brightness of the screen backlight, select a different
DISPLAY PANEL BACKLIGHT
(see Section C.1.5).
Help
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2-1
CD25 Conductivity Detector
MAIN SCREEN
DETAIL SCREEN
METHOD
---
E
!
"
Main Power
Switch Actuator
Ta b
(for opening
the door)
Figure 2-1. CD25 Front Panel
2.1.2 Control Panel Keypad
The buttons on the front panel keypad are used to affect screen functions,
to directly control CD25 operat ion, and to create and modif y programmed
series of timed events, called methods. For example, pressing
turns the method clock off
displays a list of availa ble screens. In summary:
To go from a menu to a screen, press the number button that
corresponds to the screen’s number on the menu, or move the cursor
to the desired screen name and press
Hold
(
Knob
(for a d ju s tin g
the contrast)
) and on
Run
, while pressing
(
)
Enter
.
#
Hold/Run
Menu
2-2
To edit a reverse video entry field on a screen, move the cursor to the
field using the four directional arrow buttons. Then, use the numeric
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2•Description
Keypad
Buttons
Offset
Mark
buttons to enter variable values or the
Select
∆
and
Select
∇
to choose predetermined values.
In most cases, confirm the selected value, by pressing either a cursor
arrow button or
must press
METHOD SAVE TO
the
command, the
NOTE A beep sounds each time you press a keypad button,
and a lower frequency beep sounds whenever an
error occurs. You can disable the beeps from the
MODULE SETUP
Function
Returns the analog (recorder) output to a predetermined baseline and
zeros the display. The resultant value of the offset required is displayed
on the
Sends a 10% positive event mark to the analog (recorder) output. A
mark is typically used to indicate a sample injection. This fun ction can
be programmed in a method.
Enter
. In certain fields and/or screens, however, you
Enter
to confirm the selected value. These exception s are
field, the
DIAGNOSTIC TESTS
DETAIL
screen. This function can be programmed in a method.
METHOD RUN
field, any calibration
screen, and all menu screens.
screen (see Section C.1.5).
buttons
Insert
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Inserts a new step into a method.
T o add a new s tep, mov e the cur sor to the
A new blank step appears below the cursor position. After entering a
time value, press
order and they will be automatically reorganized in the correct
chronological order.
Enter
or a cursor arrow button. Insert steps in any
TIME
field and pr
ess
Insert
.
2-3
CD25 Conductivity Detector
Keypad
Buttons
Delete
Hold/Run
Function
Removes the value from the curren t entry field. To restore the previous
value, move the cursor from the field before entering a new value.
Pressing
METHOD
Delete
when the cursor is in a step entry field on the
screen “blanks” the step parameter value. Moving the cu rsor
to another field does not restore the previous value; instead, the step
remains blank, indicating no change from the previous step .
To delete an entire method step:
1. Position the cursor in the method’s time field and press
Delete
.
The time is removed and the help line prompts you to press
Delete
again to delete the step.
2. Press
Turns the method clock off (
Delete
again. Or, to restore the original time and step
parameters, press any button except
Hold
) and on
Delete
(Run)
.
. This button
functions only when the detector is under Method control (see
Section 2.5.3).
When the method clock is in Hold, pressi ng
Hold/Run
starts the clock
at either the initial step of a new method or, if resuming an interrupted
method, at the time at which the clock was put in Hold.
2-4
Rese
Select
and
Select
When the method clock is in Run, pressing
Hold/Run
stops the
method clock, thereby “holding” the method and freezing the current
conditions.
t
Changes the method clock time to
INIT
, causing the initial conditions
specified by the method to occur. This button functions only when the
detector is under Method control (see Section 2.5.3).
If the method is running, it continues running. If the method is in Hold,
the method clock executes the initial conditions and holds.
∆
When the cursor is positioned at a field with predetermined
parameters, these buttons cycle through the options. In fields with
∇
predetermined numerical values, pressing
Select
Enter
Select
button increases (or decreases) the value
by one unit; pressing
Holding down a
continuously. Press
∇ decreases the value by one unit.
or a cursor arrow button to confirm the
Select
increases the value
∆
selected value.
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2•Description
Keypad
Buttons
Help
Menu
Numeric
Buttons
Function
The four cursor buttons move the cursor, in the direction of the arrow,
to the next entry field. If there is no changeable field in that direction,
the cursor moves diagonally or remains in its current location.
In most cases, after entering a new value in an entry field, pressing an
arrow button saves and/or executes the change. The exceptions are the
METHOD SAVE T O
command, the
DIAGNOSTIC TESTS
field, the
METHOD RUN
screen, and all menu screens.
field,
any calibration
Displays a help screen with information pertaining to the current entry
field.
Displays one of two menus, depending on the current screen:
From an operational screen, pressing
SCREENS
From a diagnostic screen, pressing
DIAGNOSTIC MENU
MENU of SCREENS
.
; pressing
.
Menu
displays the
Menu
once returns you to the
Menu
again returns you to the
MENU of
Enters numeric values into the current e ntry field. The numer ic buttons
are 0 through 9 and the decimal.
From a menu screen, pressing a numeric button opens the
corresponding screen.
Enter
Doc. 031687-01 04/2000
Saves and/or executes changes made in entry fields. I f a menu screen is
displayed, pressing
Enter
opens the highlighed screen.
2-5
CD25 Conductivity Detector
2.1.3 Initial Display Screens
When the CD25 has successfully powered-up and passed all diagnostic
tests, the
the
power-up, the
screen. See Section C.2.7 if this occurs.
POWER-UP
MAIN
screen (see Figure 2-3). If one of the diagnostic tests fails at
DIAGNOSTIC TEST
screen (see Figure 2-2) displays briefly, followed by
screen disp lays instead of the
MAIN
NOTE The information on the
reviewed at any time by selecting the screen from
DIAGNOSTIC MENU
the
CD25 CONDUCTIVITY DETECTOR
MODULEWARE REV
Help M essag e
Figure 2-2. Power-Up Screen
+2. 34
uS
POWER-UP
.
TOTA L 138.71 uS
RANGE
screen can be
BIO S REV n.nn
SRS
n.nn
nnnnnnDX L-AN ID#
50
1000 uS
2-6
LOCAL
H e lp Mess a g e
MAIN
The
facilitate viewing from a d istance. Operating parameters (flow rate,
method number to run, etc.) are selected here.
screen dis plays status information in enlarged characters to
METHOD 05
Figure 2-3. Main Screen
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2•Description
To access other screens, press the
display the
MENU of SCREENS
Menu
(see Figure 2-4). T o select an opti on, move
the cursor to a screen name and press
on the keypad and press
Enter
. See Appendix C for a description of each
screen.
MENU of SCREENS
MAIN SCREEN
1
DETAIL SCREEN
2
METHOD
3
- - -
4
5
6
7
8
Help Message
Figure 2-4. Menu of Screens
button on the front panel to
Enter
, or enter the screen number
MODULE SETUP
ANALOG OUT SETUP
TIME FUNCTION IN
DIAGNO STIC MENU
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2-7
CD25 Conductivity Detector
2.2 Electronics Chassis
The electronics chassis is located immediately behind the front door of the CD25 .
The chassis contai ns several el ectronics ca rds (printe d circuit boa rds) that ar e used
to control the CD25. Various connectors on the cards allow communication
between the CD25 and other system modules and accessories. Figure 2-5
identifies the cards and their connectors.
Do not remove any of the electronics card s from the detector.
There are no user-serviceable components on the cards. If
servicing is required, it must be performed by qualified
personnel using appropriate electrostatic discharge (ESD)
handling procedures.
Figure 2-5. CD25 Electronics Chassis Components
#"
!
$
!"
2-8
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2.2.1 Connectors
Recorder (Slot 2)
This connector is typi cally used for a recorder/integrator or diagnostic
instruments. For a description of the connector pinouts, see Table F-1 in
Appendix F. For connection instructions, see Section B.2.7.
DS3 (Slot 2)
The control cable from the DS3 Detection Stabilizer connects here.
SRS® (Slot 2)
The control cable from the Self-Regener at ing Suppressor® conne ct s her e.
Conductivity Cell (Slot 3)
The conductivity cell cable connects here.
TTL/Relay (Slot 4)
This strip of eight connectors provides an interface with Dionex and nonDionex modules for TTL and relay control of the detector. See
Appendix D for a description of relay and TTL functions and the
connections between the CD25 and other modules.
2 • Description
60-pin Ribbon Connector (Slot 5)
The 60-pin ribbon cable to the CD25 front panel (display and keypad)
connects here.
2.2.2 Cards
Power Supply Card
Provides 45 watts of power for the detector electronics.
Blank Card
Slot 1 contains a blank card that must be present to complete the
electromag netic interference (EMI) shielding.
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2-9
CD25 Conductivity Detector
SCR (Supply Control/Relay) Card
Interfaces to the CPU; th e card contains three functions:
16-bit Recorder Output Digital-to-Analog Converter
electronic switch for selection of full-scale outputs of 0.01, 0.1, and
1.0 V.
SRS Power Supply
50, 100, 300, or 500 mA to the suppressor. An over-voltage detector
shuts off the power i f the vol tage ex cee ds 8.5 V. An over- temp eratur e
detector shuts off the power if the SRS temperature excee ds 40
either of these events o ccurs, the S CR card sends an “SRS Alarm”
error message to the CPU.
DS3 Power Supply
Stabilizer . While warmi ng or coolin g to a lowe r set poin t, a “BELOW
TEMP” or “ABOVE TEMP” message is displayed. Once a set point
in the range of 25 to 45
maintains a constant temperature .
SP (Signal Processor) Card
—Includes an
—Supplies a regulated current (set by the user) of
°
C. If
—Supplies heating power to the DS3 Detection
°
C is reached, proportional heat control
2-10
Contains all the analog circuitry needed by the CD25, as well as the
digital circuitry required to interface to the CPU. See Appendix E for a
list of SP ca rd functions.
Relay/DX-LAN and CPU Cards
The CD25 control Moduleware and BIOS reside on the CPU card.
The CPU card provides control and monitoring of other modules. A
60-pin ribbon cable assembly links the logic to the CD25 front panel
display a nd keypad .
The Relay I/O card provides two isolated low voltage relay outputs,
two TTL outputs, and four TTL inputs.
The cards are installed in slot 5 of the card cage. The Relay card is a halfcard which rides piggyback on the CPU card and sits behind slot 4.
The Relay I/O card is short enough to allow th e optional detector interface
card (P/N 044196) to be mount ed behi nd it in slot 4. The interface card is
required for communica tion bet ween the CD25 an d PeakNet so ft ware via
the DX-LAN.
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2 • Description
Power Supply LED
The multicolored LED below the TTL/Relay connections indicates the
power supply status:
A green LED indicates normal operation.
A red LED indicates a fault conditi on. When a fault occurs, th e CD25
enters its diagnostic state and no other control is permitted until the
problem is corrected. Turning off the power for a few seconds may
clear the fault; however, if the red LED is lighted when you turn on
the power again, notify Dionex.
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2-11
CD25 Conductivity Detector
2.3 Conductivity Cell
The flow-through conductivity cell has an active volume of about 1.0 µL. T wo
316 stainless stee l elect rodes are permanentl y sealed into the PEEK cell bo dy. The
cell constant has a nominal value of 160 cm
sensor located slightly downstream from the electrodes senses the temperature of
liquid passing thro ugh the cell. The me asured value is used to provid e temperature
compensation.
The advanced geometry of the cell provides several benefits:
Excellent accuracy and linearity over the working range
Efficient sweepout and low volume for low dispersion
Reduced sensitivity to electrode surface conditions
Low electrode mass
Effective temperature compensation
You can order the conductivity cell installed in a DS3 Detection Stabilizer
(P/N 044130) for temperature control, or installed in an electrical shield
(P/N 044132) which provides no temperature control. Bec ause th e DS3 maintai ns
a constant temperature, thus reducing the effects of variations in laboratory
temperature, the DS3 is recommended for conductivity detection.
-1
and is calibrated electronically. A
2-12
Temperature Control and Compensation
Temperature directly affects the conductivity of a solution. As conductivity
increases, the effect of temperature changes becomes more pronounced. For
example, building temperature control systems can cause a regular oscillation in
the baseline. This, in turn, can affect the reproducibility of an analysis.
In ion chromatography, suppressing eluent conductivity minimizes the effect of
temperature variation. Temperature compensation further improves baseline
stability. When the conductivity cell is housed in a DS3 Detection Stabilizer, the
DS3 enhances the ability of these techniques to reduce temperature effects below
the detection limit.
Temperature compensation also ensures that th ere will be no major chang e in the
baseline or peak heights, should it be necessary to change the DS3 operating set
°
point. Readings will be normalized to 25
C.
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2.3.1 DS3 Detection Stabilizer
The DS3 is a temperature-controll ed chamber c onsisting of a cast
aluminum base and cover enclosed in insulating foam. The chamber
houses both the conductivity cell and the eluent heat exchanger.
Figure 2-6 identifies the major components of the DS3.
The DS3 provides the following benefits:
Conductivity measurements that are nearly impervious to laboratory
temperature variation
Very low dispersion in the eluent heat exchanger
Excellent peak height reproducibility
Remote mo unting after either the column or suppressor
User-settable temperature
Power input to a pair of trans istors on op posite sid es of the DS3 heat s it to
°
a set temperature from 25
outlet senses the eluent temperature. The CD25 circuitry compares this
temperature with the user-selected temperature and adjusts the heat input
in real time to hold the temperature within a few millidegrees.
C to 45 °C. A sensor near the heat exchanger
2 • Description
The DS3 is sealed with an O-ring to trap eluent that may leak from the
cell. If 5 mL of liquid acc umulates, a thermistor s ensor becomes
immersed and signals a leak to the CPU. Any additional leakage will be
discharged via the spill/overflow line. A second thermistor, above the
discharge level, acts as a temperature re ference for the leak sensor.
Doc. 031687-01 04/2000
2-13
CD25 Conductivity Detector
To Detector
Electronic s
Conductivity Cell
Ground Wire
Ce ll Inlet
Figure 2-6. DS3 Detection Stabilizer
2.3.2 Shielded Cell
A conductivity cell installed in an electrical shield (P/N 044132) is
available. The shield is a stainless steel housing that protects the cell from
electromagnetic interference (EMI), but does not provide temperature
control.
DS3
Inle t
DS3
Outlet
Sp ill/Overflo w
Line
DS3
Enclosure
Keyhole Mounting
Slots
2-14
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2.4 Rear Panel
The CD25 rear panel (see Figure B-1) contains fuses, connectors for line power,
and a connection for the optional DX-LAN interface.
DX-LAN Connection (Optional)
When you order the DX-LAN network, a DX-LAN connector is factory-installed
in the upper left corner of the CD25 r ear panel (see Figure B-1). See Appendix B
for DX-LAN interface connection instructions.
External Connection Access
Connections to the front of the electronics chassis, such as TTL and relay cables,
are usually rout ed to t he back of the d etector through t he cab le chase in the bo ttom
of the electroni cs chass is. The y may also be pass ed throug h slots at the front o f the
detector. Cables exit the CD25 through an opening in the rear panel (see
Figure B-1).
2 • Description
Doc. 031687-01 04/2000
2-15
CD25 Conductivity Detector
2.5 Functional Description
2.5.1 Operating and Control Modes
The operating mode determines
how
the CD25 receives operating
commands:
In Local mode, the CD25 receives commands from the front control
panel buttons and screens.
In Locked Remote mode, PeakNet 6 software sends commands from
the host computer via the DX-LAN interface.
The control mode determines
In Direct control, the CD25 executes commands immediately.
In Method control, the CD25 executes commands according to the
when
operating commands are executed.
timed steps in a method. The method is programmed from the CD25
front panel.
The table below summarizes the various operating and control mode
MAIN
configurations. Select the modes from the
Section C.1.2),
DETAIL
screen (see Section C.1.3), or chromatography
screen (see
software.
Operating/Control Mode Detector Operation
Local/Direct Control Commands are entered from the CD25 front control
panel and executed immediately after being entered.
2-16
Local/Method Commands are entered from the CD25 front control
panel and executed by running a method programmed
from the front panel.
Locked Remote/Direct
Control
Commands are sent from PeakNet 6 and executed
immediately when received.
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2.5.2 Local and Remote Modes
Local Mode
When the CD25 is powered up, it is a lways in Loc al mode. In Loc al mode
the detector accepts operating commands from two sources:
Direct input from the front panel keypad and screens. All operating
functions are available with direct input.
TTL inputs from a remote controller (for example, a Dionex gradient
pump module or an integrator). TTL signals can be used to offset the
recorder, run a method, turn the SRS off and on, send a mark to the
recorder, and increase the recorder range.
Locked Remote Mode
In Locked Remote mode, the CD25 accepts operating commands from a
Dionex data station via the DX-LAN.
In Locked Remote mode, all operating changes from the front panel are
disabled. Selecting the Connect command from PeakNet 6 immediately
selects the Locked Remote mode. To return the CD25 to Local mode,
select the Disconnect command, or turn off the CD25 power.
2 • Description
2.5.3 Method Control
In Method control, commands are executed according to the time-based
steps specified in a metho d. Methods are crea ted, edite d, and saved on the
METHOD
instructions.
METHOD EDIT SAVE TO
TEMP COMP
TIME
INIT
0.00
2.00
Help M essag e
Doc. 031687-01 04/2000
screen (see Figure 2-7). See Section 3.3 for programming
RUN
RANGE
200 uS
v
1.6
OFFSET MARK
**
Figure 2-7. Method Screen
3333
SRS 100DS3 TEMP 40
TTL RLY
1
0
1
25
212
000
1
2-17
CD25 Conductivity Detector
The following summarizes basic information about using methods:
The CD25 can run under method control while you are entering or
editing any method (including the one that is currently running).
When saving changes to the currently running method, or switching
to a different method, the method cloc k continue s running unaf fected.
Only those p arameter changes which affect the method after the
current time will be implemented in the current run.
The CD25 can store up to 100 separate methods (0 through 99) in
memory. The actual number, which depends on the size of each
method and the amount of available memory, is typically less than
this.
Methods are retained in memory even after the CD25 is powered
down.
Each method can have a maximum of 32 time-based steps. Step 1
always starts at
0.0.
INIT
(initial conditions). Step 2 always starts at
TIME
=
2-18
Doc. 031687-01 04/2000
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