MKS HPS I-MAG 423 Series User manual

HPSTM Products
Series 423 I-MAG®
Cold Cathode Ionization
Vacuum Sensor
OPERATION AND
MAINTENANCEMANUAL

Please Note:
MKS Instruments provides these documents as the latest version for the revision indicated.
The material is subject to change without notice, and should be verified if used in a critical
application.

Cold Cathode Ionization Vacuum Sensor
HPSTMProducts
Series 423 I-MAG®
ColdCathodeIonization
VacuumSensor
September 1997
PART #104230020 REV. B

Cold Cathode Ionization Vacuum Sensor
Part#10423000X
Serial # __ __ __ __ __ __
Please fill in these numbers and have
themreadilyavailablewhencallingfor
serviceoradditionalinformation.
(Thepartnumbercanbefoundonyour
packing slip, and both the part number
andserialnumberarelocatedonthe
bottom side of the housing.)
© 1999 by MKS Instruments, Inc., HPSTM Products Inc., All rights reserved.
ALCONOXisaregisteredtrademarkofAlconox,Inc.
IgniTorrisatrademarkofMKSInstruments,Inc.,HPSTM ProductsInc.
InconelisaregisteredtrademarkofIncoAlloysInternational,Inc.
Scotch-Briteisatrademarkof3M.
SensaVacisaregisteredtrademarkofMKSInstruments,Inc.
For more information or literature, contact:
MKS Instruments, Inc., HPSTM Products Inc.
5330 Sterling Drive
Boulder, CO 80301 USA
Phone: [phone]
800-345-1967
FAX: [phone]

Cold Cathode Ionization Vacuum Sensor
Table of Contents
Table of Contents
Package Contents ..................................................................... 1
SafetyInformation...................................................................... 2
Symbols .................................................................................................. 2
Symbols Used in this Manual (English) ....................................................................... 2
Symboles utilisés dans ce manuel (Français) ............................................................ 3
In dieser Betriebsanleitung vorkommende Symbole (Deutsch) ................................. 4
Símbolos Usados en el Manual (Español) .................................................................. 5
Safety Precautions .................................................................................. 6
English........................................................................................................................... 6
Français ........................................................................................................................ 6
Español ......................................................................................................................... 6
Deutsch......................................................................................................................... 6
Specifications............................................................................ 7
Feature Locations...................................................................... 8
About the HPSTM Series423 I-MAG®Sensor.............................. 9
Installing and Using the Series 423 I-MAG®Sensor................ 10
Locating andOrienting theSensor ..........................................................10
ConnectingtheSensor ...........................................................................10
Starting the Sensor ................................................................................10
OperatingtheSensor..............................................................................11
PreparingforBakeout .............................................................................11
Maintaining the Series 423 IMAG®Sensor .............................. 12
ContaminationoftheSensor...................................................................12
Disassembly...........................................................................................12
Cleaning .................................................................................................13
Assembly ...............................................................................................13
Accessories / Spare Parts ....................................................... 16
ProductWarranty ..................................................................... 17
NOTES.................................................................................... 18

Cold Cathode Ionization Vacuum Sensor

1
Cold Cathode Ionization Vacuum Sensor
Package Contents
Before unpacking your Series 423 I-MAG®Cold Cathode Ionization
Vacuum Sensor, check all surfaces of the packing material for
shipping damage.
Please be sure that your Series 423 I-MAG®Sensor package contains
these items:
1 I-MAG®Sensor
1 HPS™ Series 423 I-MAG
®
Cold Cathode Ionization Vacuum
Sensor User's Guide.
If any items are missing from the package, call HPSTM Customer
Service at 1-303-449-9861 or 1-800-345-1967.
Cables are required for connecting the I-MAG®Sensor to its
controller but are sold separately. Please refer to page 14 for
necessary ordering information.
Inspect the I-MAG®Sensor for visible evidence of damage during
shipment. If it has been damaged, notify the carrier immediately.
Keep all shipping materials and packaging for claim verification. Do
not return the product to HPSTM.
t
t
(

2
2Cold Cathode Ionization Vacuum Sensor
DefinitionsofCAUTION and NOTE
messagesusedthroughoutthemanual.
CAUTION: Risk of electrical shock. ISO
3864, No. B.3.6
CAUTION: Refer to accompanying
documents. ISO 3864, No. B.3.1
This sign denotes a hazard. It calls
attention to a procedure, practice,
condition, or the like, which, if not
correctly performed or adhered to, could
result in injury to personnel.
This sign denotes a hazard. It calls
attentiontoanoperatingprocedure,
practice, or the like, which, if not
correctlyperformedoradheredto,
could result in damage to or
destruction of all or part of the
product.
This sign denotes important
information. It calls attention to a
procedure,practice,condition, orthe
like, which is essential to highlight.
Symbols Used in this Manual
(English)
Safety Information
Symbols
FF
FF
F

3
Cold Cathode Ionization Vacuum Sensor
Symboles utilisés dans ce
manuel (Français)
Définition des indications ATTENTION et
REMARQUE utilisées dans ce manuel.
ATTENTION: Risque de secousse
électrique. ISO 3864, No. B.3.6
ATTENTION: Se reporter à la
documentation. ISO 3864, No. B.3.1
L’indication signale un danger potentiel.
Elle est destinée à attirer l’attention sur
une procédure, une utilisation, une
situation ou toute autre chose présentant
un risque de blessure en cas d’exécution
incorrecte ou de non-respect des
consignes.
L’indication signale un danger
potentiel.Elle est destinée à attirer
l’attentionsur une procédure, une
utilisation, une situation ou toute autre
choseprésentantunrisque
d’endommagement ou de dégât d’une
partie ou de la totalité de l’appareil en
casd’exécutionincorrecte oude non-
respectdesconsignes.
L’indicationREMARQUEsignaledes
informationsimportantes.Elleest
destinéeàattirerl’attention surune
procédure, une utilisation, une
situationoutouteautre chose
présentantunintérêtparticulier.
FF
FF
F

4
4Cold Cathode Ionization Vacuum Sensor
Definition der mit VORSICHT! und
HINWEIS überschriebenen Abschnitte in
dieser Betriebsanleitung.
VORSICHT! Stromschlaggefahr!
ISO 3864, Nr. B.3.6
VORSICHT! Bitte Begleitdokumente
lesen! ISO 3864, Nr. B.3.1
Das Symbol VORSICHT! weist auf eine
Gefahrenquelle hin. Es macht auf einen
Arbeitsablauf, eine Arbeitsweise, einen
Zustand oder eine sonstige Gegebenheit
aufmerksam, deren unsachgemäße
Ausführung bzw. Ungenügende
Berücksichtigung zu Körperverletzung
führen kann.
DasSymbol VORSICHT! weist auf eine
Gefahrenquelle hin. Es macht auf
einenBedienungsablauf,eine
Arbeitsweiseodereinesonstige
Gegebenheitaufmerksam,deren
unsachgemäßeAusführungbzw.
UngenügendeBerücksichtigungzu
einerBeschädigungoderZerstörung
des Produkts oder von Teilen des
Produktsführenkann.
Das Symbol HINWEIS weist auf eine
wichtige Mitteilung hin, die auf einen
Arbeitsablauf,eineArbeitsweise,einen
Zustandodereinesonstige
Gegebenheitvonbesonderer
Wichtigkeitaufmerksammacht.
In dieser Betriebsanleitung
vorkommende Symbole
(Deutsch)
FF
FF
F

5
Cold Cathode Ionization Vacuum Sensor
Definiciones de los mensajes de
PRECAUCIÓN y OBSERVACIÓN
usados en el manual.
PRECAUCIÓN: Riesgo de descarga
eléctrica. ISO 3864, N.° B.3.6
PRECAUCIÓN: Consultar los
documentos adjuntos. ISO 3864, N.°
B.3.1 Esto símbolo indica un riesgo.
Pone de relieve un procedimiento,
práctica, condición, etc., que, de no
realizarse u observarse correctamente,
podría causar lesiones a los empleados.
Esto símbolo indica un riesgo. Pone
derelieve unprocedimiento, práctica,
etc., de tipo operativo que, de no
realizarseuobservarsecorrectamente,
podríacausardesperfectosal
instrumento, o llegar incluso a causar
su destrucción total o parcial.
Esto símbolo indica información de
importancia. Pone de relieve un
procedimiento,práctica,condición,
etc.,cuyoconocimientoresulta
esencial.
Símbolos Usados en el Manual
(Español)
FF
FF
F

6
6Cold Cathode Ionization Vacuum Sensor
English
Safety Precautions
High voltages are present in the Sensor during operation.
High voltage is present in the cable and the Sensor when a controller is
turned on.
Dangerdehautetension .
Une haute tension est présente dans le câble et dans le capteur lorsque le
contrôleur est sous tension.
Hochspannungsgefahr!
Bei eingeschaltetem Steuerteil liegt im Kabel und im Sensor Hochspannung
an.
Peligro por alto voltaje.
Cuando el controlador está encendido, se registra alto voltaje en el cable y
en el sensor.
Español
Français
Deutsch

7
Cold Cathode Ionization Vacuum Sensor
Specifications
Design and/or specifications subject to change without notice.
Measuring Range 3.0 x 10-11 to 1.0 x 10-2 Torr
4.0 x 10-11 to 1.3 x 10-2 mbar
4.0 x 10-9 to 1.3 x 100Pa
3.0 x 10-8 to 1.0 x 101microns
Repeatability Approximately ±5%
Operating Temperature Range 0° to 70°C (32° to 158°F)
Maximum Bakeout Temperature 500°C (932°F) for CF flanged unit,
without cable and magnet
Installation Orientation Any, vacuum port face down
suggested
Internal Volume 0.9 in.3(15.0 cm3) maximum
Materials Exposed to Vacuum SS 304, SS 302, aluminum, glass,
Inconel®X-750, alumina ceramic
External Materials ABS plastic, stainless steel,
aluminum, Ceramic 5 (magnets)
Diameter 2.6 in. (66 mm)
Height (with CF Flange) 3.4 in. (86 mm)
Typical Weight (with CF Flange) 1.8 lb (0.8 kg)
Vacuum Connection KF 25, KF 40, 2¾" CF (rotatable),
1" tubing
Controller Compatibility HPSTM Series 421, 929, 937, 941,
953, and MKS Type 146

8
8Cold Cathode Ionization Vacuum Sensor
1
2
3
4
234
6-32 x 0.25" Flat Head Countersunk Screw (2)
(For Removal of Magnet for Bakeout)
HighVoltageFeedthroughPin
IonCurrentFeedthroughPin
1
Sensor Tube Vacuum Port
Feature Locations
TM

9
Cold Cathode Ionization Vacuum Sensor
HE SERIES 423 I-MAG®COLD CATHODE IONIZATION SENSOR is a smaller,
less expensive version of our Series 421 Sensor. The I-MAG®
Sensor uses the same isolated collector design previously unique to the
Series 421 Sensor. Experimentally, the isolated collector has proven to
provide continuous pressure measurement to 10-11 Torr.
With an output equivalent to the Series 421 Sensor, the I-MAG®
Sensor, together with its cable, is fully compatible with all
HPSTM cold cathode sensor controllers, as well as the
MKS Type 146 vacuum sensor measurement and
control system.
Additional features include a
removable magnet,
replaceable internal
components, no elastomers or
any other high outgassing materials
in vacuum, compact size, low mass,
low internal volume, and excellent
resistance to thermal shock.
Cables for the I-MAG®Sensor include
circuitry to protect the user from shock and to
protect the controller's sensitive electrometer against
excessive voltage.
T
About the HPSTM Series
423 I-MAG®Sensor

10
10 Cold Cathode Ionization Vacuum Sensor
Installing and Using the Series
423 I-MAG®Sensor
Locating and Orienting the Sensor
Locate the I-MAG®Sensor where it can measure process chamber or
manifold pressure. Install it away from pumps, other vibration sources, and
gas sources to give the most representative values. The magnetic field of
the Sensor should also be kept away from ion or electron beam sources.
Locate and orient the I-MAG®Sensor where contamination is least likely. If
it is installed directly above a diffusion pump, for example, oil vapor could
contaminate the cathode, anode, or other vacuum exposed components,
causing the calibration to shift.
The I-MAG®Sensor can be installed with the body set in any direction.
Operating position does not affect accuracy. Installing it with the vacuum
port facing down is optimal as this helps prevent contaminants falling into it.
Operation at pressures above 10-3 Torr for extended periods will
increase the likelihood of contamination.
Connecting the Sensor
Mount the Sensor to a grounded vacuum system.
If the I-MAG®Sensor has a CF flange, remove the magnet first to allow
clearance for bolt installation. When replacing the magnet, note that it is
keyed to the sensor body to protect the feed through pins from damage. The
pins should be straight and centered.
Use an all-metal clamp to mount a KF 25 or KF 40 flanged sensor body.
Connect the cable to the Sensor and to your controller before turning on
your system. Tighten the thumb screw on top of the cable to make sure it is
securely in place and for strain relief.
Starting the Sensor
The I-MAG®Sensor starts quickly in the rough to medium vacuum ranges.
In the UHV pressure range, starting may be delayed by several minutes.
Use a HPSTM IgniTorr™ Cold Cathode Starting Device to help significantly
reduce starting time (see Accessories, p. 16).

11
Cold Cathode Ionization Vacuum Sensor
Operating the Sensor
Operation at pressures above 10-3 Torr for extended periods will
increase the likelihood of contamination.
High voltage should be disabled at pressures above 10-2 Torr to
prevent sputtering.
Preparing for Bakeout
Loosen the thumb screw on top of the cable and remove it. Loosen the two
flathead screws located on top of the Sensor, and then remove the magnet.
The remainder of the Sensor is ready to be baked out to 500°C if using a
CF flange or to 150°C if using a KF flange.

12
12 Cold Cathode Ionization Vacuum Sensor
For this chapter, please refer to the figure shown on page 15.
Contamination of the Sensor
If pressure readings appear to be erratic, the Sensor tube may be
contaminated. Inspect it visually. If contamination is visible, you should
replace the internal components with an Internal Rebuild Kit (see
Accessories, p. 16).
Depending on the degree of contamination and application of the Sensor,
the internal parts may be cleaned — either ultrasonically, with mild
abrasives, or chemically.
Disassembly
Tools required: clean tweezers; clean, smooth-jaw, needle-nose pliers
1Loosen the thumb screw on top of the sensor cable and then
remove it. Loosen the two flat head screws . Remove the
magnet .
2Using the smooth-jaw, needle-nose pliers, firmly grab the
compression spring at the tip closest to the flange.
3Pull on the compression spring while rotating it to free it from the
formed groove of the sensor body . Continue to pull until the
compression spring is completely free.
4Carefully remove the remaining components from the sensor body .
Do not bend the anode or the leaf spring on the ion current
feed through pin when assembling or disassembling the
Sensor as they are very fragile and could break.
Maintaining the Series 423
IMAG®Sensor
FF
FF
F
1
7
89
13
14 15

13
Cold Cathode Ionization Vacuum Sensor
Cleaning
If ultrasonic cleaning, use high quality detergents compatible with
aluminum, such as ALCONOX®.
Scrubbing with mild abrasives can remove most contamination.
Scotch-Brite™ or a fine emery cloth may be effective. Rinse with alcohol.
Clean aluminum and ceramic parts chemically in a wash, such as a 5 to
20% sodium hydroxide solution (not for semiconductor processing), at room
temperature (20°C) for one minute. Follow with a preliminary rinse of
deionized water. Remove smut (the black residue left on aluminum parts
due to this process) in a 50 to 70% nitric acid dip for about 5 minutes.
Chemical cleaning should not be used to clean the anode; mild
abrasivesorultrasoniccleaningareacceptable.
Do not damage the leaf spring while cleaning the Sensor.
Each of the above cleaning methods should be followed with multiple rinses
of deionized water.
Dry all internal components and the sensor body in a clean oven. The
two ceramic spacers , and , are slightly porous and will require longer
drying time in the oven to drive off the absorbed water.
Assembly
Wear gloves and assemble with clean tools.
1Check the anode . It should be straight and centered with the
sensor body for proper operation.
2Roll the sensor body on a flat surface and look for any radial
runoutmotion.
3Install the ground shield using tweezers. Make sure that at the
groove of its larger diameter, the ground shield interlocks with the
locating collar .
4Slide the small ceramic spacer over the small end of the
ground shield . Check that the leaf spring will contact the
base of the cathode as shown to the right. If not, remove the
small ceramic spacer and the ground shield . Gently bend the leaf
spring towards the anode , and then replace the ground shield
and ceramic spacer .
FF
FF
F
FF
FF
F
25
6
11
4
7
8
7
5
69
8

14
14 Cold Cathode Ionization Vacuum Sensor
5Slide the cathode , the grid washer , and the large ceramic
spacer into place. The grid washer has a concave shape. Refer
to the figure to see its installation orientation.
6Insert the small end of the compression spring into the sensor
body . Using your thumbs, push the larger end of the spring into
the sensor body until it is contained within the tube's inside
diameter. Using the smooth-jaw, needle-nose pliers, work the
compression spring down into the sensor body until it is fully seated
in the formed groove.
7Inspect the ground shield and the grid washer to verify they
are centered with respect to the anode . If adjustment is needed,
gently reposition the grid washer/cathode assembly, taking care not
to scratch the grid washer .
Wesuggestyoumeasuretheresistancebetweenthe ioncurrent
feed through pin and the grid washer to verify that the leaf
spring is in contact with the cathode . The measurement
should indicate a short circuit between them. There should be
an open circuit between the ion current feed through pin and
both the high voltage feed through pin and sensor body .
The I-MAG®Sensor is ready for installation. If it is not immediately
installed, cover the flange with clean, vacuum grade aluminum foil and
cap it with a flange protector.
3
2
1
36
7
8
9
10
13
4
3
13 7
FF
FF
F4
Leaf spring in
contact with
cathode