Varian sentorr Instruction Manual

senTorr

™

Gauge
Controller

Instruction Manual

Varian Vacuum Technologies
121 Hartwell Avenue
Lexington, Massachusetts 02421
[phone]

Manual No. 6999-08-165
Revision G
February 1999

Telephone Numbers

U.S. only 1-800-8-VARIAN (1-800-882-7426)

From Alaska and Hawaii, dial [phone]

Order Entry (Sales)............Press 1........

FAX [phone]

Technical Support............Press 2........

FAX [phone]

Field Service............Press 3........

FAX [phone]

Training (Information

and Registration)............Press 4........

FAX [phone]

Service

Canada

Telephone ..................1-800-663-2727 (Canada Only)

[phone]

FAX ..................[phone]

France

Telephone ..................(33) 16-986-3838

FAX ..................(33) 16-928-2308

Germany (Darmstadt)

Telephone ..................(49) 61-51-70-32-05

FAX ..................(49) 61-51-70-32-79

Italy

Telephone ..................(39) 11-997-9111

FAX ..................(39) 11-997-9350

Japan

Telephone ..................(81) 3-3588-9732

FAX ..................(81) 3-3449-4597

Korea

Telephone ..................(82) 3-333-665-5171

FAX ..................(82) 3-333-665-0115

UK

Telephone ..................(44) 932-234-741

FAX ..................(44) 932-228-769

Copyright © by Varian Associates, Inc.

Reserved, including the right of reproduction in whole or in part in any form, without

permission in writing from Varian Vacuum Products, Lexington, MA 02421

November, 1995

WARRANTY

Products manufactured by Seller are warranted against defects in materials and workmanship for
twelve (12) months from date of shipment thereof to Customer, and Seller’s liability under valid war­ranty claims is limited, at the option of Seller, to repair, replacement, or refund of an equitable portion
of the purchase price of the Product. Items expendable in normal use are not cov ered by this warranty .
All warranty replacement or repair of parts shall be limited to equipment malfunctions which, in the
sole opinion of Seller, are due or traceable to defects in original materials or workmanship. All obliga­tions of Seller under this warranty shall cease in the event of abuse, accident, alteration, misuse, or
neglect of the equipment.In-warranty repaired or replacement parts are warranted only f or the remain­ing unexpired portion of the original warranty period applicable to the repaired or replaced parts. After
expiration of the applicable warranty per iod, Customer shall be charged at the then current pr ices for
parts, labor, and transportation.

Reasonable care must be used to avoid hazards. Seller expressly disclaims responsibility for loss or
damage caused by use of its Products other than in accordance with proper operating procedures.

When products are used with toxic chemicals, or in an atmosphere that is dangerous to the health of
humans, or is environmentally unsafe, it will be the responsibility of the Customer to have the product
cleaned by an independent agency skilled and approved in handling and cleaning contaminated mate­rials before the product will be accepted by Varian Associates for repair and/or replacement.

Except as stated herein, Seller makes no warranty, express or implied (either in fact or by operation of
law), statutory or otherwise; and, except as stated herein, Seller shall have no liability under any war­ranty, express or implied (either in fact or by oper ation of law), statutory or otherwise. Statements made
by any person, including representatives of Seller, which are inconsistent or in conflict with the terms
of this warranty shall not be binding upon Seller unless reduced to writing and approved by an officer
of Seller.

Warranty Replacement and Adjustment

All claims under warranty must be made promptly after occurrence of circumstances giving rise
thereto, and must be received within the applicable warranty period by Seller or its authorized repre­sentative.Such claims should include the Product serial number, the date of shipment, and a full
description of the circumstances giving rise to the claim. Before any Products are returned for repair
and/or adjustment, written authorization from Seller or its authorized representative for the return and
instructions as to how and where these Products should be returned must be obtained. Any Product
returned to Seller for examination shall be prepaid via the means of transportation indicated as accept­able by Seller. Seller reserves the right to reject any warranty claim not promptly reported and any war­ranty claim on any item that has been altered or has been returned by non-acceptable means of
transportation. When any Product is returned for examination and inspection, or for any other reason,
Customer shall be responsible for all damage resulting from improper pac king or handling, and for loss
in transit, notwithstanding any defect or non-conformity in the Product, in all cases, Seller has the sole
responsibility for determining the cause and nature of failure, and Seller's determination with regard
thereto shall be final.

If it is found that Seller’s Product has been returned without cause and is still serviceable, Customer
will be notified and the Product returned at its expense; in addition, a charge for testing and examina­tion may be made on Products so returned.

8/15/95

i

Hazards

Operators and service personnel must be aware of all hazards associated with this equipment.They
must know how to recognize hazardous and potentially hazardous conditions, and know how to avoid
them.The consequences of unskilled, improper, or careless operation of the equipment can be seri­ous. this product must only be operated and maintained by trained personnel. Every operator or ser­vice person must read and thoroughly understand operation/maintenance manuals and any additional
information provided by Varian Associates.All warnings and cautions should be read carefully and
strictly observed. Consult local, state, and national agencies regarding specific requirements and reg­ulations. Address any safety, operation, and/or maintenance questions to your nearest Varian office.

The following format is used in this manual to call attention to hazards.

W ARNING

_____________

Warnings are used when failure to observe instructions or precautions
could result in injury or death to humans.

CAUTION

________

Cautions are used when failure to observe instructions could result in
significant damage to equipment and/or facilities.

NOTE

________

Notes contain information to aid the operator in obtaining the best per­formance from the equipment.

ii

An independent agency has determined that all vacuum chambers regardless of manufacture, can
possibly become charged to lethal voltage levels, under certain conditions, if they are not grounded
with a quality, common ground with the controller of their ionization tube.

After each maintenance/service procedure and before operating the controller and vacuum system,
verify the integrity of the ground of both units;failure to do so could cost you your life!

W ARNING

_____________

Check that your Ion Gauge Controller and vacuum system are sepa­rately grounded to a common ground.

Placement of a ground wire between the vacuum chamber and the con­troller chassis is not safe;large continuous currents could flow through it.

Personnel could be killed by high voltages (160 to 900 volts may be pre­sent in an improperly grounded system).

Make absolutely sure that your v acuum system is g rounded as shown in
the following schematic diagr am;test the system ground be sure that it is
complete and capable of supporting at least 10 amperes.

iii

W ARNING

_____________

This equipment contains high voltages (up to 3000 volts), high enough to
produce electric shock and cause death or serious injury.

Equipment utilizing these controls should be designed to prevent per­sonal contact with high voltages.

Always break the primary circuit when direct access to the control unit is
required.

EMC Warnings

This is a Class A product. In a domestic environment this product may cause radio interference in
which case the user may be required to take adequate measures.

FCC

This device complies with Part 15 of the FCC rules. Operation is subject to the following two condi­tions: (1) This device may not cause harmful interference , and (2) this device must accept any interfer­ence received, including interference that may cause undesired operation.

NOTE

________

The equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC rules.These limits
are designed to provide reasonable protection against harmful interfer­ence when the equipment is operated in a commercial environment.This
equipment generated, uses, and can radiate radio frequency energy
and, if not installed and used in accordance with the instruction manual,
may cause harmful interference to radio communications. Operation of
this equipment ina residential area is also likely to cause harmful radio
communications interference in which case the user will be required to
correct the interference at his own expense.

Installation Requirements

To maintain compliance with both the FCC Part 15 rules and the European Union’s EMI directives the
user must use a shielded cable constructed of a braided shield for the analog outputs and setpoint
wiring. Metal or metallized plastic backshells directly connected to the cable shield at the 9 pos D-Sub
connector if using serial communications.The shields of all I/O cables must be connected to ground at
the users equipment. Failure to install the equipment.Failure to install the equipment in this way may
result in the unit no longer meeting the requirements for radiated emissions and susceptibility.

Table Of Contents

Page

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

I INTRODUCTION AND DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1-1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1-2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1-3 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1-4 Part Numbers and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1-5 Serial Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

II PREPARATION FOR USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2-1 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2-2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

III OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3-1 Keypad Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Option Select Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Enter Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

UP and DOWN Arrows (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Stdby Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Units Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Cal Key (All models w/TCs or ConvecTorrs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Stpt Hyst Key (All models, with set point option) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Emis Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Baud Rate Key (All models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Degas Key (BA2, BA2c, BA, UHV, UHV2c models, with degas option) . . . . . . . . . 3-2

3-2 Parameter Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3-3 Set Point Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3-4 Set Point Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3-5 Recorder Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

3-6 TC and ConvecTorr Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3-7 Access Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3-8 Software Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3-9 Display Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3-10 Battery Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3-11 Accessing Second Filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

IV TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4-1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4-2 Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4-3 Changing Line Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4-4 Application Footnotes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Gas Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Programming Emission mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Emission mA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Programming Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Appendix A Gas Correction Factor Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Section 1

INTRODUCTION AND DESCRIPTION

1-1 GENERAL

Varian’s senTorr Gauge Controller is a complete, half-rack vacuum gauge controller that offers contin­uous, reliable pressure measurement from rough to high vacuum.The controller comes completely
configured from the factory to operate one of six gauge tube configurations.

UHV2c Two convectorrs and one UHV type HFIG
BA2 Two Thermocouples and one Bayard-Alpert gauge tube
BA2c Two ConvecTorrs and one Bayard-Alpert gauge tube
CC2 Two Thermocouples and one Cold Cathode gauge tube
CC2c Two ConvecTorrs and one cold cathode gauge tube
BA One Bayard-Alpert gauge tube

CC One Cold Cathode gauge tube

The senTorr Gauge Controller features one digital display per gauge tube .The displays are LED-driven
providing clear and sharp pressure readings.The front panel keypad has practical loc kout features that
protect against unauthorized parameter inputs.Analog outputs and remote capabilities are located on
the back panel.The external remote input controls turnon or turnoff of high-vacuum gauge emission.

Options include set points and RS232 or RS485/422 communication ability. Resistive (I

2

R) degas is an
option on Bayard-Alpert models, E-beam degas on the UHV models.The set point option includes four
set points, one for each gauge tube plus an additional set point that can be assigned to any one of the
three gauge tubes.

The senTorr offers an extraordinary amount of gauging and programming capability while still remain­ing easy to use.The operator can access all of the instrument's functions and parameters through the
front panel keypad or the optional serial link.

1-2 SPECIFICATIONS

Power Requirements 90 to 127 VAC, 50/60 HZ

208 to 250 VAC, 50/60 HZ
The senTorr is fitted with an internal switch to accommodate the desired power input.
Operating Temperature 0 to 50°C
The senTorr meets all performance specifications (unless otherwise noted) at 25°C (+5°C) at 90 per-

cent relative humidity, non-condensing.
Data Retention The senTorr will retain its parameter values, upon power down or a power

failure, for a period of four years accumulated off-time.
Size Half-rack mount, 3.5" high by 8.0" wide by 15" deep
Optional rack-mounting kits are available for mounting one or two units in a standard 19-inch rack.

Cabling The senTorr basic unit includes a 6-foot power cord and fuse set.Gauge

cabling is available separately. Standard gauge cable lengths are 10, 25,

50, 75, and 100 feet.Longer cables (up to 500 feet) are available by special

order.All cable connections are made at the rear of the unit.

1-1

Introduction and Description

Varian cannot guarantee compliance with FCC regulations for radiated emissions unless all external
wiring is shielded. (See page iii)

HFIG Gauge (BA2, BA2c, BA, UHV, UHV2c models)
Minimum pressure 1.3 x 10

-7

Pa/1 x 10-9Torr (BA)

capability 5.3 x 10

-9

Pa/4 x 10

-11

Torr (UHV)

Maximum pressure 1.3 x 10

-1

Pa/1 x 10-3Torr (standard BA and UHV)

capability 1.3 x 10

1

Pa/1 x 10-1Torr (broad-range BA)

Degas (optional) Resistive, 1 hour timeout

E-beam (UHV), 15 minute timeout

Sensitivity – Adjustable from 1330/Pa (10/Torr) standard BA default value

1.33/Pa to 1.31 x 10

4/

Pa 1064/Pa (8/Torr) broad range BA default value

(1/Torr to 99/Torr) 3325/Pa (25/Torr) UHV default value
Emission current 4 mA (standard BA and UHV)

(Adjustable from 0.1 mA (broad range BA)

0.1 mA to 9.9 mA)
Analog output 1 V/decade

0 V for “OFF”, “- -”, and “xxE” conditions
Optional Linear Recorder Out available

Auto-on (standard) available on BA2, BA2c, and UHV2c configurations only,

set to TC1 only

Cold Cathode Gauge (CC2 CC2c, IMG, IMG2c models)
Minimum pressure 1.3 x 10

-6

Pa/1 x 10-8Torr (CC models)

capability 5.3 x 10

-9

Pa/4 x 10

-11

Torr (IMG models)

Maximum pressure 1.3 Pa/1 x 10

-2

Torr

capability
Operating voltage –2 kV (CC models)

+3 kV (IMG models)

Sensitivity – Adjustable from (5 A/Torr) CC default value
133A/Pa to 1.31 x 10

4

A/Pa (2 A/Torr) IMG default value

(1 A/Torr to 99 A/Torr)
Analog output 1 V/decade

Optional Linear Recorder Out available

Auto-on (standard) available on CC2, CC2c, IMG2c configurations only, set to TC1 only
Thermocouple and Convectorr Gauge (BA2, CC2, BA2c, CC2c, UHV2c, IMG2c models)

Minimum pressure 1.3 x 10

-1

Pa/1 x 10-3Torr

capability
Maximum rated 266 Pa/2 Torr (TC models)

pressure capability 1.3 x 10

5

Pa/1000 T orr (ConvecTorr models)

1-2

Introduction and Description

Heater current 165 mA ± 10% (TC models)
Calibration 1.3 x 10

-1

Pa/1 x 10-3Torr (vacuum)

(two points) 1.0 x 10

5

Pa/7.6 x 102Torr (atmosphere)

Auto-on threshold 1.3 x 10

-1

Pa to 6.6 Pa (1 x 10-3Torr to 5 x 10-2Torr)

(available on TC1 only)
Analog output 1 V/decade

1 V at 1.3 x 10

-1

Pa/1 x 10-3Torr

7 V at 1.3 x 10

5

Pa/1000 T orr
10 V for “03E” condition
Optional Linear Recorder Out available

Set Points (all models with Set Point option)
Set Points floating SPDT relays with NO, NC, and C terminals
Contact rating 3 A at 24 VDC/250 VAC, gold-flashed

Remote Input (all models)
Input 3 to 32 VDC, 500 ohms minimum to activate high-vacuum gauge

(optically-isolated and floating level-sensitive)

Options Available

Bayard-Alpert Configurations

Up to three optional plug-in printed circuit boards can be user-installed in the UHV, UHV2c, BA2,
BA2c, and BA configurations, with the f ollo wing restrictions:one set point board, one degas board, and
one communications board, either RS232 or RS485/422.

Cold Cathode Configurations

Up to two optional plug-in printed circuit boards can be user-installed in the CC2, CC2c, and CC con­figurations, with the following restrictions: one set point board and one communications board, either
RS232 or RS485/422

1-3 FRONT PANEL

The front panel display of the senTorr 7-segment, LED digits and LED annunciators.These provide con­tinuous, crisp readings, with no directional bias.The display uses three LED colors to group information.

Green pressure data and parameter values
Yellow set point and parameter annunciators
Red operational status legends

1-3

To determine the ordering number, select the desired configuration as follows:

Basic Configurations

One Ion Gauge

BA – Bayard-Alpert (563, 564, 571, 572, 580) . . . . . L 9 1 2 0 3 0 1 X X 0 X

CC – Standard Cold Cathode (524, 525) . . . . . . . . . L 9 1 2 1 3 0 1 X X 0 X

UHV – Ultra-High-Vacuum Nude Gauge (UHV-24) . . L 9 1 1 0 3 0 1 X X 0 X

IMG – Ultra-High-Vacuum Inverted Magnetron . . . . . L 9 1 1 1 3 0 1 X X 0 X

One Ion Gauge, Two Thermocouple Gauges

BA2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 2 0 3 0 2 X X 0 X

CC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 2 1 3 0 2 X X 0 X

One Ion Gauge, Two ConvecTorr Gauges

BA2c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 2 0 3 0 3 X X 0 X

CC2c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 2 1 3 0 3 X X 0 X

UHV2c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 1 0 3 0 3 X X 0 X

IMG2c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L 9 1 1 1 3 0 3 X X 0 X

Setpoint Options

No Setpoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0

Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Degas Options

No Degas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0

Degas (BA resistive, UHV E-Beam) . . . . . . . . . . . . . 1

Communications Options

No Communications . . . . . . . . . . . . . . . . . . . . . . . . . 0

RS-232 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RS-232 Fiber Optic. . . . . . . . . . . . . . . . . . . . . . . . . . . 2

RS-422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

RS-485 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Introduction and Description

A single pressure display features four digits, two for the mantissa and two for the exponent. There is a
pressure readout for each gauge, with the Bayard-Alpert or Cold Cathode display labeled “IG”and the
two thermocouple or ConvecTorr displays labeled “TC1” and “TC2”, as applicable to the senTorr model.

Label pressure displayed
IG Bayard-Alpert or Cold Cathode

(depending on the model)

TC1 Thermocouple one or ConvecTorr one
TC2 Thermocouple two or ConvecTorr two

The column of red LED legends indicates the following operational states.

Degas hot filament ion gauge is degassing
Emis On ion gauge is on
Auto-On auto-on feature is programmed
mBar pressure measurements units are mBar
Torr pressure measurement units are Torr
Cal calibrating thermocouples or ConvecTorrs
Hyst programming set point hysteresis

The keypad is a sealed membrane-type, with tactile feedback.There are eleven keys, some of which
are dual function.

1-4

Introduction and Description

1-4 PART NUMBERS AND DESCRIPTIONS

1-5 SERIAL COMMUNICATION

The senTorr offers computer interface options allo wing complete operation of the unit remotely via ser­ial link.The RS232 option consists of a plug-in printed circuit board (Varian part no. L9141301) avail­able with either a 9-pin, D-subminiature connector or fiber optic connectors (fiber-optic board, Var ian
part no. L9141302). It allows complete operation of the Multi-Gauge via a computer using serial com­munication. All of the keypad functions (except for the baud rate settings and the display output) are
accessible through the RS232 bi-directional computer link.

The RS485/422 computer interface option is available as a plug-in printed circuit board (Varian part no.
L9143301). This senTorr option provides serial communications capability as specified in EIA
(Electronic Industry Association) standard 422 and 485. Both employ differential line drivers and
receivers, and are capable of communicating to distances of 4000 feet at 19,200 baud in a multidrop
scheme, with up to 32 senTorr units.

Refer to Varian manual 6999-08-170 provided with the serial communication option for further information.

1-5

Introduction and Description

1-6

Section II

PREPARATION FOR USE

2-1 UNPACKING

Each senTorr unit is inspected and carefully packed prior to shipment. If the unit arrives damaged,
save the packing material and immediately notify the carrier. Because the packing materials are
designed specifically for this instrument, they should always be used when transporting the unit.The
shipping container is packed with the following contents.

1 senTorr Basic Unit
1 A-C line cord
1 Instruction Manual
4 rubber adhesive feet for bench top use of the senTorr

2-2 INSTALLATION

Before operating the unit, it is necessary to set it for the proper line voltage level.

1. Open the unit by removing the two screws at the top rear of the unit then pivot the cover up

and back to disengage the front lip.Lift off the cover.

2. Set the line voltage by moving line voltage selector switch S1 (Figure 2-1) to either the 115 VAC
(for 110 VAC or 115 VAC, 50/60 Hz) or 230 VAC position (for 220 VAC or 240 VAC, 50/60 Hz).

3. Before replacing the top cover, check that switch S1 is correctly positioned, that all cables are
properly plugged in, and there is no loose hardware or metal parts inside the senTorr unit.
Replace the cover and secure it with the two screws.

4. Mount the unit using the desired rack-mounting kit, then attach the appropriate external
gauge and system cables.Refer to Figure 2-2 for rear panel connections and Figure 2-3 for
mounting dimensions.

2-1

NOTE

________

The unit is shipped with switch S1 (internal) set to 230 VAC.

W ARNING

_____________

Before servicing the unit, check that the line cord is not plugged into a
power source.Obser ve all warnings and cautions printed on the cover.

2-2

Preparation for Use

Figure 2-2. Rear Panel Connections

Figure 2-1. Setting Line Voltage

2-3

Preparation for Use

Figure 2-3. Panel Cutout Dimensions

Note: Bezel Trim Kit R0130301 can be used to hide gaps between senTorr case and panel)

2-4

Preparation for Use

Section III

OPERATION

3-1 KEYPAD FUNCTIONS

Refer to Figure 3-1 for the locations of the keys and display features described in following par ag r aphs .
Following each key name are the senTorr models and the option (if any) to which the function applies.
Note that some of the keys may not work unless a particular option has been installed.

1. Option Select Key (All Models)

Pressing the “Option Select” key puts the senTorr into the Program mode, as indicated by the flashing
yellow annunciator. Repeated “Option Select” key presses single-steps the annunciator through the
column of set points and parameters, returning the senTorr to the Run mode after the last key press.
“Option Select” also acts as an “escape” key when pressed before the “Enter” key has been used to
store a new digit setting.

Read Section 3-2, Parameter Programming, for further information.

2. Enter Key (All Models)

Pressing the “Enter” key advances the flashing cursor through a selected Program mode, and saves
the setting when pressing “Enter” after the last digit.

3. UP and DOWN Arrows (All Models)

These keys are used to increment and decrement, respectively, digit values when entering data.

4. Stdby Key ( All Models)

Pressing the “Stdby”key will power off all of the display, the fan, and the ion gauge tube.This is a low
power shutdown;the unit will continue to provide power to the processor.

5. Units Key (All Models)

Pressing the “Units” key toggles the pressure measurement units between Torr, mBar and Pascal for
all pressure readings.The front panel legends will reflect the pressure units, with both the Torr and
mbar lamps extinguished for Pascal.

6. Cal Key (BA2, BA2c, UHV2c, CC2, CC2c, IMG2c Models)

This key is used to calibrate the vacuum and atmosphere readings for the thermocouple gauges. The
red “Cal”legend will light when calibrating the TC's or ConvecTorrs.

7. Stpt Hyst Key (All Models, with set point option)

Used in conjunction with the “Option Select” program mode to display or program the set point hys­teresis values.The red “Hyst”legend will light to indicate that the set point pressure being displayed is
the hysteresis level (see para. 3-3).

3-1

Operation

9. Baud Rate Key (All Models)

This key is used to display and set the serial communications baud rate, parity, and the controller
address (for use in a multi-drop communication link.

After pressing “Baud Rate”, the baud rate will flash in the IG display mantissa. Use the arrow keys to
select a baud rate of 1.2 (1200), 2.4 (2400), 4.8 (4800), 9.6 (9600), or 19 (19,200).

Press “Enter” to save the current flashing value as the baud rate and to advance to the parity setting,
displayed in the IG display exponent. Use the arrow keys to select parity of O (Odd), E (Even), or “n”
(none).

Press “Enter” to save the parity setting and to advance to the controller address setting, displayed in
the IG mantissa. Use the arrow keys to select an address from 00 to 99.Once again, press “Enter” to
save the address and exit the baud rate settings. This paragraph applicable to the RS 485/422 ONLY.

The default settings are 9600 baud with no parity and an address of 00.

10. Degas Key (BA, UHV Models, with degas option)
Can only activate if the pressure at the Bayard-Alpert ion gauge is less than 10

-3

Pa/10-5Torr.Pressing
the “Degas” key will illuminate the hidden degas legend to reflect the state of the degas.Pressing the
Degas key again will turn the degas function off.After engagement, the degas will automatically turn
off after approximately 1 hour, for I

2

R degas, 15 min for E-beam.The degas option must be installed to

operate this function; if the user does not purchase the degas option, then this key has no effect.

3-2

Figure 3-1. Front Panel, senTorr Gauge Controller

8. Emis Key (All Models)

Pressing “Emis”turns the high vacuum gauge on or off.The hidden “Emis On” legend will light to reflect
the on state of the ion emissions.The high vacuum gauge emissions will come on only if the appropri­ate vacuum has been achieved.

8. Emis Key (BA/UHV dual filament models)

Pressing the “Enter”key before pressing “Emis”uses the second filament.

Operation

3-2 PARAMETER PROGRAMMING

The set point and ion gauge parameters listed in a column on the front panel display (see Figure 3-1)
can be viewed or programmed by putting the senTorr into the Program mode.To the left of each para­meter is a single yellow LED.

If the yellow LED is flashing, that parameter is selected to the Progr am mode and its value is displayed
in the corresponding gauge readout.

If the yellow LED is lit solidly, that menu item is active, meaning that the set point is energized or the
ion gauge parameter has been changed from its default setting.

Enter the Program mode by pressing the “Option Select” key.The first available parameter, beginning
from the top of the column and depending on the senTorr models and options installed, will flash in the
appropriate gauge display. Repeated “Option Select”key presses will advance through the parameters,
returning the unit to the Run mode after the last key press.

When the desired parameter has been selected, the up and down arrow keys can be used to set a
new value to the flashing digit.The “Enter”key will advance the flashing through the digits, saving the
new value after the last digit has been set.

3-3

NOTE

________

If the yellow LED is left flashing in the Program mode unattended for
more than 5 seconds, the default will automatically return the annuncia­tor to the Run mode.

A changed value will not be saved unless it has been “Entered” through
all of its digits.The “Option Select”key can be used to “escape”from sav­ing a changed value prior to “Enter”ing the last digit.

After the value has been saved, the whole setting will flash. Press “Enter” to re-program the value, or
“Option Select” to advance to the next parameter. The senTorr will exit the Program mode if no keys
are pressed for about 8 seconds.

To disable a set point, set its mantissa to “0.0”.
IG Setpt (All Models with Set Point option)

The ion gauge set point can be set to energize when the ion gauge pressure drops below the IG Setpt
threshold setting. It will de-energize when the ion gauge pressure goes above the IG Setpt hysteresis
setting (refer to Para.3-3, Set Point Hysteresis).The IG Setpt pressure will flash in the IG display. Use
the up and down arrow ke ys and the “Enter” key to set the digit values and advance through the digits .

TC1 Setpt (All models with Set Point option)
The TC1 set point can be set to energize when TC1 reads less than the TC1 Setpt threshold setting.

It will de-energize when the TC1 pressure goes above the TC1 Setpt hysteresis setting (refer to Para.
3-3, Set Point Hysteresis).The TC1 Setpt pressure wll be displayed in the TC1 readout.

Operation

TC2 Setpt (All models with TC or Convectorrs with Set Point option)

The TC2 set point can be set to energize when TC2 reads less than the TC2 Setpt threshold setting.
It will de-energize when the TC2 pressure goes above the TC2 Setpt hysteresis setting (refer to Para.
3-3, Set Point Hysteresis).The TC2 Setpt pressure wll be displayed in the TC2 readout.

Add’l Setpt (All Models with Set Point option)
The additional set point can be assigned to any of the gauges.When this parameter is selected, all

three pressure displays will flash.Press the “Enter” key to assign the Add’l Setpt to the ion gauge,
using the standard parameter programming method.If no value is set in the ion gauge display (man­tissa = 0.0), the “Enter”key can be pressed again to assign the Add’l Setpt to TC1, or likewise to TC2.

Auto-On (BA2, BA2c, CC2, and CC2c Models)
The Auto-On function assigns TC1 as the turn-on source for the ion gauge.Press “Option Select” until

the Auto-On Setpt annunciator is flashing.The Auto-On setting will be displayed in the TC1 readout.
The turn-on pressure can be set from 1.3 x 10

-2

Pa to 6.6 x 10-1Pa (1.0 x 10-3Torr to 5.0 x 10-3Torr)

and additionally between 1.3 Pa to 6.6 Pa (1.0 x 10

-2

Torr to 5.0 x 10-2Torr), using the standard para-

meter programming method.
The ion gauge will turn on when TC1 reaches the programmed pressure.When the TC1 pressure rises

10 percent above the programmed Auto-On pressure, the ion gauge will turn off.
The Auto-On feature can be temporarily overridden by pressing the “Emis” key to turn the ion gauge

off.It will go back into effect after the TC1 pressure rises above the programmed Auto-On pressure.
GasCorr (All Models)

The gas correction factor adjusts the ion gauge pressure calculation depending on the system gas.
The gas correction value will be displayed in the IG readout. The default setting is 1.0, for N

2

(air).The

setting can range from 0.1 to 9.9.
Refer to Appendix A for the Table of Gas Correction Factors.
Emis mA (All Models)

The emission current setting controls the hot filament gauge emission current.The programmed value
will flash in the IG display.Use the standard parameter programming method to select a value from 0.1
mA to 9.9 mA.The default setting is 4 mA for standard gauges and 0.1 mA for broad-range Bayard­Alpert gauges (Varian models 564 and 580).

If the emission current is set less than or equal to 1.0 mA, it remains constant over all pressures.If the
emission current setting is greater than 1.0 mA, it will be automatically reduced to one-tenth of the set­ting at pressures greater than 6.6 x 10

-2

Pa (5 x 10-5Torr).This feature extends filament life.

Ion Sens (All Models)
The ion gauge sensitivity compensates for the different gauge geometries.The current setting will flash

in the IG display. Refer to Page 1-2 for the default sensitivity settings.

3-4

Operation

3-5

3-3 SET POINT HYSTERESIS

A set point will energize when the pressure of its pre-assigned gauge drops below the set point's pro­grammed threshold pressure.The set point will de-energize when the gauge pressure rises above the
set point hysteresis pressure.The set point hysteresis automatically defaults to 10 percent above the
threshold value.This value can be changed by pressing the “Stpt Hyst” key.The red Hyst legend will
light to indicate that the set point pressure being displayed is the hysteresis level.

The “Stpt Hyst”key will not function if the set point has not been programmed.

3-4 SET POINT RELAYS

CAUTION

________

The relay contacts are gold-flashed, making them suitable for logic-level
switching.However, the application of AC or DC voltages greater than 20
V or 20 VA will cause erosion of the gold, even in just one switching cycle.

Refer to Figure 3-2 for set point option.

Find Part # Description Qty on

This Sheet

1 L9132002 Set Point Assy 1
2 641309621 Bracket 2
3 614412132 Screw 4
4 L6419301 Cable 1

5 5140687800 Connector Mate 4

Figure 3-2. Set Point Option

Operation

3-6

Figure 3-3. Assembling the Cable

3-5 RECORDER OUTPUT

Recorder output for each gauge is provided at the back of the unit. A two-conductor Micro Jax con­nector is plugged into each output.Varian strongly recommends the use of shielded wiring (coaxial
cable) to maintain compliance with FCC regulations for radiated emissions. Refer to Figure 3-3 to
assemble the cable.Any recorder with an imput impedance greater than 2,000 ohms and a full-scale
input range of +10 V can be used.

The output reflects the displayed pressure of the gauges. Refer to Figures 3-4a and 3-4b for standard
and linear output characteristics of the recorders.

Ion Gauge Algorithm:

Converting recorder output voltage to pressure

To calculate the pressure from the voltage output

Example recorder output = 4.28 volts DC

To get the exponent, take the integer part of voltage output which is 4 and subtract 11:

4 – 11 = –7 (E-7)

To find the mantissa, take the fractional portion and add .1 to it and divide by .11

(.28 + .1)/.11 = 3.45

therefore:

4.28 VDC = 3.45E-7 Torr

TC ConvecTorr Algorithm:

Converting recorder output voltage to pressure

To calculate the pressure from the voltage output

Example recorder output = 3.28 volts DC

To get the exponent, take the integer part of voltage output which is 3 and subtract 4:

3 – 4 = –1 (E-1)

Now to find the mantissa, take the fractional portion and add .1 to it and divide by .11:

(.28 + .1)/.11 = 3.45

therefore:

3.28 VDC = 3.45E-1 Torr

Operation

3-7

Figure 3-4a. Standard Recorder Output Characteristics

Operation

3-8

Pressure Pressure Voltage

≥133 Pa ≥1E +0 Torr 10

1.3 E1 Pa 1E-1Torr 1

6.6 Pa 5E-2Torr 0.5

1.3 Pa 1E-2Torr 0.1

≤1.3E-1 Pa ≤ 1E-3Torr 0.01

Error E03 Error E03 10.156 (over scale)

Optional Linear recorder output for TC configuration (requires optionally puchased firmware)

Full Scale Full-Scale Access

Setting Setting Code

1.3E-1 Pa 1E-3 Torr 93 (Default)

1.3E-2 Pa 1E-4 Torr 94

1.3E-3 Pa 1E-5 Torr 95

1.3E-4 Pa 1E-6 Torr 96

Linear recorder output option for BA and CC configurations

Pressure Pressure Voltage

≥1.3E-1 Pa ≥ 1E -3 Torr 10

1.3E-2 Pa 1E-4 Torr 1

6.6E-3 Pa 5E-5 Torr 0.5

1.3E-3 Pa 1E-5 Torr 0.1

≤1.3E-4 Pa ≤ 1E-6 Torr 0.01

Exx/Off Exx/Off 0

Using a full-scale setting of 1E-3 Torr as an example:

Figure 3-4b. Optional Linear Recorder Output Characteristics

Operation

3-9

3-6 TC AND CONVECTORR CALIBRATION

Expose the desired thermocouple or ConvecTorr to either atmospheric pressure or to a vacuum
greater than 1.3 x 10

-1

Pa (1 x 10-3Torr).

Press the “Cal” key once to calibrate TC1, or twice to calibrate TC2.The respective pressure display
will flash either 1 x 10

5

Pa/7.6 x 102Torr (if the TC has been reading 1.3 x 101Pa/1.0 x 10-1Torr or

above) or 1.3 x 10

-1

Pa/1.0 x 10-3Torr (if the TC had been reading less than 1.3 x 101Pa/1.0 x 10

-1

Torr).
Press the “Enter” key to save the calibration point, or press “Cal”to exit the calibration procedure.
Repeat the procedure for each TC at each end point.

3-7 ACCESS CODES

The senTorr offers several hidden features available through the keypad.This provides some protec­tion for the operator and the system by requiring knowledge of the access code for the desired func­tion.The access code is entered through the keypad sequence “Enter”then “Units”. Use the up and
down keys to select the appropriate two-digit code, displayed in the IG readout, using the standard
parameter programming method.The codes and their respective functions are:

Code Function

33 A Unlock keypad (default)
27 A Lock keypad, except for Enter, Units, and arrow keys (to allow further access code entry)
17 A Lock keypad, except for Enter, Units, arrow, Emis, and Degas keys (to prevent

parameter changes)

81 A Reset total system. All parameters except the baud rate settings revert to defaults, and

the ion gauge turns off
71 A Resets TC calibrations to system defaults
61 A Removes all set point programming.
39A Set Bayard-Alpert parameters (sensitivity, emission current, and over-pressure shutdown) to

standard Bayard-Alpert values (default)

49 A Set Bayard-Alpert parameters (sensitivity, emission current, and over-pressure shutdown) to

broad-range Bayard-Alpert (Varian models 564 and 580) values

79 A Set thermocouple or ConvecTorr pressure update to slow, allowing more stable readings

through data averaging (default)

89A Set thermocouple or ConvecTorr pressure update to fast, allowing faster response to pressure

changes
56A Enable E02 (pressure burst) and E06 (grid error) fault protection
52 A Disable E02 (pressure burst) and E06 (grid error) fault protection. The senTorr will override

these faults, for systems that are able to handle pressure spikes

3-8 SOFTWARE REVISION

The software revision can be displayed by pressing “Enter” then the down arrow.The revision will light
in the IG display for several seconds.

Operation

3-10

3-9 DISPLA Y TEST

By pressing “Enter” and the “Up” arrow, the entire display can be lit for several seconds.This feature
can be used to verify LED function.

3-10 BATTERY BACKUP

The senTorr uses a lithium battery and CMOS RAM for storage of all system parameters during power
outages or when powered down.Upon restoring power, the senTorr verifies the RAM content.If the
RAM is good, the parameters will remain as previously saved; if the RAM is corrupted, all parameters
will be reset to their default values.

If the ion gauge was on when power was lost, emission will NOT automatically be re-established
unless the TC Auto-On function was programmed to do so.

3-11 ACCESSING SECOND FILAMENT

See Section 3.1, step 8 “EMIS Key” for controlling dual filament tubes.

4-1

W ARNING

_____________

For continued protection against fire, both fuses must be replaced with
fuses of the same type and rating as originally supplied;T, 5A, 250 V.

4-3 CHANGING LINE FUSES

On rare occasions, it may be necessary to change the AC line fuses due to age , o v erload, etc.There are
two fuses which are located on the top of the power entry module marked with the outline of the fuses.

The fuses can be accessed by prying out the cover of the fuse holder with a small screwdriver after
removing the power cable. The small fuse board can then be slid out of the holder by lifting the black
plastic retainer.Refer to Figure 4-1, Fuse Replacement.

Section IV

TROUBLESHOOTING

4-1 GENERAL

These troubleshooting procedures are provided to aid the operator in identifying failure modes. For fur­ther troubleshooting assistance or for the replacement of a board or unit, contact Varian Vacuum
Products Service at 1-800-882-7426.

4-2 ERROR CODES

O2 E Pressure burst caused by a sudden rise in pressure at the ion gauge.
O3 E No ion current or measurement signal (e.g., bad or missing collector cable connection; bad

electrometer; emission current too low; cold cathode pressure less than minimum pressure

capability – see Specifications page 1-2)
O4 E Filament overcurrent (shorted filament circuit)
O5 E Filament undercurrent (open filament); cable not connected, bad control circuit or not

installed correctly
O6 E Grid voltage low ( grounded grid, bad grid supply)
O7 E Overtemperature (temperature inside unit over 65°C)
O8 E Board logic failure (bad component, electrical noise)
O9 E Overpressure (indicated pressure above high pressure limit of the ion gauge)
12 E Underpressure (indicated pressure beyond minimum pressure of ion gauge)
13 E Insufficient current (dirty cold cathode gauge, open cable connection)
14 E Invalid keypress (locked keypad)

Troubleshooting

4-2

4-4 APPLICATION FOOTNOTES

Gas Correction

The gas correction factor tables are reproduced for the convenience of the user and do not imply that
use with other gases will be safe with filament gauge controllers.

The senTorr gauge controller is normally calibrated to read pressure in nitrogen.To automatically con­vert readings of the senTorr to a different gas speciesd, enter the relative gas correction constant
through the front panel key functions.

By entering the gas correction constant, the gauge will divide the result by the gas correction constant and
display the correct adjusted value .Howe ver, a proper understanding for the transformation is required.The
correction for the different gas species is purely mathematical.The sensitivity of the tube is affected by dif­ferent gases, which, in turn, are responsible f or the tube outpute being manipulated b y the pressure equa­tion.There will be some loss in resolution of the instrument when gas correction factors are used.The loss
in resolution will become more apparent as the correction factors approach 0.5 from either direction.

When the correction constants are 0.1 or 10, the tube output is 1/10 or 10 times normal.This will
cause the instrument to lose the high vacuum decade, respectively.

Programming Gas Correction

Enter the Program mode by pressing the “Option select” key.The first available parameter, beginning
from the top of the column and depending on the senTorr model and options installed, will flash in the
appropriate gauge display. Repeated “Option Select”key presses will advance through the parameters,
returning the unit to the Run mode after the last key press.

Figure 4-1. Power Entry Module

Troubleshooting

4-3

When “Gas Corr” has been selected, the up and down arrow keys can be used to set a new value to
the flashing digit.The “Enter” key will advance the flashing through the digits, saving the new value
after the last digit has been set.

Emission mA

The Emission current is set to 4.00 mA as a default.The emission current will remain constant (4 mA) as
long as the pressure is less than 1.3 x 10

-3

Pa/1 x 10-5Torr.The senTorr automatically reduces the cur-

rent by a factor of 10 when the pressure is greater than 6.6 x 10

-3

Pa/5 x 10-5Torr.Thus, the emission
current would drop to 0.4 mA.This promotes an extended pressure r ange measurement capability and/or
prolongs tube life by protecting the filament.

Emission current can be adjusted from 10 µA to 9.99 mA through the keypad on the front panel of the
senTorr unit. One reason why a user might possibly consider lowering the emission current is to pre­vent a small fluctuation in a pressure reading that may occur when operating just below 1.3 x 10

-3

Pa/

1 x 10

-5

Torr and just above 6.6 x 10-3Pa/5 x 10-5Torr.If emission current is adjusted to <1 mA, the

current will remain constant throughout the entire pressure range.
Another reason why a user might consider lowering the emission current pertains to the applications

that require higher pressure readings from the gauge tube.The lower the emission, the higher in pres­sure the tube is able to measure.This also applies in the opposite direction; the higher the emission
current is raised, the lower in pressure the tube can measure.

Programming Emission mA

Enter the Program mode by pressing the “Option Select” key.The first available parameter, beginning
from the top of the column and depending on the senTorr model and options installed, will flash in the
appropriate gauge display. Repeatedly pressing the “Option Select”key will advance through the para­meters, returning the unit to the Run mode after the last key press.

When “Emis mA” has been selected, the up and down arrow keys can be used to set a new value to
the flashing digit.The “Enter” key will advance the flashing through the digits, saving the new value
after the last digit has been set.

Sensitivity

Default Sens Tube

3325/Pa 25/T UHV 24
1330/Pa 10/T 571, 572, 563

665A/Pa 5 A/T 525, 524

1064/Pa 8/T 580, 564

133A/Pa 1 A/T Inv Mag CC

To improve the accuracy of pressure measurements, sensitivity can easily be adjusted to match gauge
tube calibration.

Troubleshooting

4-4

T roubleshooting Tips

• To aid in troubleshooting and to verify the integrity of the ion gauge
controller or the cold cathode gauge itself, one can use a resistive
dummy load.Obtain a 5.6 Meg ohm, 2 watt resistor.This value will
simulate a pressure reading in the mid E-3 Pa/E-5 Torr region;
higher resistor values than this will yield a lower pressure reading
and lower resistor values will yield a higher pressure reading.

• Varian offers reference ionization B/A gauges, which are sealed off

at approximately 6.6E-4Pa/5E-6 Torr.These gauges are extremely
helpful in troubleshooting a vacuum system problem by isolating the
defective component.It is important to know that these reference
ion gauge tubes are not NIST traceable calibrated gauges but act
only as a load for the ion gauge controller

W ARNING

_____________

When connecting the resistive load to the back of the cold cathode
gauge controller, –2000 volts DC will be present. Make sure the power
is off to the unit. Keep all conductive type of material away from the
back of the controller when troubleshooting.

The Customer is responsible for taking the necessary safety precau­tions to avoid electrical shock when performing this test.

Programming Sensitivity

V arian off ers ref erence ionization B/A gauges, which are sealed off at approximately 6.6E-4 Pa/5E-6 Torr.
These gauges are extremely helpful in troubleshooting a v acuum system prob lem b y isolating the def ec­tive component.It is important to know that these reference ion gauge tubes are not NIST traceable cal­ibrated gauges but act only as a load for the ion gauge controller.

Enter the Program mode by pressing the “Option Select” key.The first available parameter, beginning
from the top of the column and depending on the senTorr model and options installed, will flash in the
appropriate gauge display. Repeatedly pressing the “Option Select”key will advance through the para­meters, returning the unit to the Run mode after the last key press.

When “Ion Sens” has been selected, the up and down arrow keys can be used to set a new value to
the flashing digit.The “Enter” key will advance the flashing through the digits, saving the new value
after the last digit has been set.

A-1

Appendix A

GAS CORRECTION FACTOR TABLE

Gas correction factor tables are only reproduced for the convenience of the user and do not imply that
use with other gases will be safe with hot filament gauge controllers.

The following tab le lists relative gauge gas correction factors for various gases.The values are deriv ed
by empirical methods substantiated by measurements reported in literature.This table has been com­piled and published by Robert L. Summers of Lewis Research Center, NASA Technical Note TND­5285, National Aeronautics and Space Administration, Washington, DC, June 1969.

To automatically convert readings of the senTorr Controller (normally calibrated for nitrogen), enter the
relative gas correction constant through the front panel key function GAS CORR. By entering the gas
constant, the gauge will divide the result by the gas correction constant and display the correct
adjusted value.However, a proper understanding for the transformation of the result is required.The
correction for different gas species is purely mathematical.The sensitivity of the tube is affected by dif­ferent gases which, in turn, are responsible for the tube output being manipulated by the pressure
equation.There will be some loss in resolution of the instrument when gas correction constants are
used.The loss in resolution will become more apparent as the correction constants approach 0.5 from
either direction.

When the correction constants are 0.1 or 10, the tube output is 1/10 or 10 times normal.This will
cause the instrument to lose the high vacuum decade or the near atmosphere decade, respectively.

Note:The default for Gas Correction is 1.

Appendix

A-2

Relative Ionization Gauge

Substance Formula Gas Correction Factor

Acetaldehyde C2H4O 2.6
Acetone (CH

3)2

CO 3.6

4.0

3.6

Acetylene C

2H2

1.9

2.0

Air 1.0

0.98

Ammonia NH

3

1.3

1.2

1.3

Amylene:

ISO· ISO·C

5H10

5.9

cyclo· CY·C5H

10

5.8

Argon Ar 1.3

1.1

1.2

0.9

Benzene C

6H6

5.9

5.8

5.7

5.9

6.0
Benzoic Acid C6H5COOH 5.5
Bromine Br 3.8
Bromomethane CH3Br 3.7
Butane:

n

· n·C

4H10

4.9

4.7

ISO· ISO·C

4H10

4.6

4.9
Cadmium Cd 2.3

3.4
Carbon Dioxide CO

2

1.4

1.4

1.5

1.5

1.4

Relative Ionization Gauge

Substance Formula Gas Correction Factor

Carbon Disulfide CS

2

5.0

4.7

4.8

Carbon Monoxide CO 1.05

1.05

1.1

Carbon Tetrachloride CCI

4

6.0

6.3

Cesium Cs 4.3

2.0

4.8

Chlorine CI

2

0.68

2.6

1.6
Chlorobenzene C6H5Cl 7.0
Chloroethane C2H5Cl 4.0
Chloroform CHCl

3

4.7

4.8

4.8
Chloromethane CH3Cl 2.6

3.2

3.1
Cyanogen (CN)

2

2.8

3.6

2.7
Cyclohexylene C

6H12

7.9

6.4
Deuterium D

2

0.35

0.38
Dichlorodifloromethane CCI

2F2

2.7

4.1
Dichloromethane CH2Cl

2

3.7
Dinitrobenzene C

6H4

(NO2)

2

o· 7.8
m

· 7.8

p· 7.6

Ethane C

2H6

2.6

2.8

2.5
Ethanol C2H5OH 3.6

2.9
Ethyl Acetate CH3COOC2H

5

5.0

Gas Correction Factor Table

Appendix

A-3

Relative Ionization Gauge

Substance Formula Gas Correction Factor

Ethyl ether (C2H5)2O 5.1

5.1

Ethylene C

2H4

2.3

2.4

2.2

2.2 to 2.5
Ethylene oxide (CH2)2O 2.5
Helium He 0.18

0.15

0.13

0.12
Heptane C7H

16

8.6
Hexadiene:

1.5

· 1.5·C

5H10

6.4

cyclo· CY·C6H

10

6.0
Hexane C6H

14

6.6
Hexene:

1

· 1·C

6H12

5.9

cyclo CY·C6H

10

6.4
Hydrogen H

2

0.46

0.38

0.41

0.45

0.44
Hydrogen Bromide HBr 2.0
Hydrogen Chloride HCl 1.5

1.6

2.0

1.5
Hydrogen Cyanide HCN 1.5

1.6
Hydrogen Floride HF 1.4
Hydrogen Iodide HI 3.1
Hydrogen Sulfide H

2

S 2.2

2.2

2.3

2.1
Iodine I

2 5.4

Iodomethane CH3I 4.2
Isoamyl Alcohol C5H11OH 2.9
Isobutylene C4H

8 3.6

Krypton Kr 1.9

1.7

1.7
Lithium Li 1.9
Mercury Hg 3.6
Methane CH

4 1.4

1.5

1.6

1.4 to 1.8

1.5

1.5

Methanol CH3OH 1.8

1.9
Mehtyl Acetate CH3COOCH

3 4.0

Mythyl ether (CH3)2O 3.0

3.0

Relative Ionization Gauge

Substance Formula Gas Correction Factor

Naphthalene C10H

8

9.7

Neon Ne 0.30

0.31

Nitrobenzene C6H5NO

2

7.2

Nitrogen N

2

1.0

Nitrotoluene (o·, m·, p·)C6H4CH3NO

2

8.5

Nitric Oxide NO 1.3

1.2

1.0

Nitrous Oxide N

2

O 1.5

1.7

1.7

1.3 to 2.1

Oxygen O

2

1.0

1.1

0.9

0.9

Pentane

n

· n·C

5H17

6.2

6.0

5.7

ISO· ISO·C

5H17

6.0

neo· (CH3)4C 5.7

Phenol C6H5OH 6.2
Phosphine PH

3

2.6
Potassium K 3.6
Propane C

3H8

4.2

3.7

3.7 to 3.9

3.6
Propene oxide C3H6O 3.9
Propene:

n

· n·C

3H6

3.3

3.2 to 3.7

cyclo· cy·C3H

6

3.6
Rubidum Rb 4.3
Silver perchlorate AgCIO

4

3.6
Sodium Na 3.0
Stannic iodide SnI

4

6.7
Sulphur Dioxide SO

2

2.1

2.3
Sulphur Hexafloride SF

6

2.3

2.8
Toluene C6H5CH

3

6.8
Trinitrobenzene C6H3(NO2)

3

9.0
Water H

2

O 1.1

1.0

0.8
Xenon Xe 2.9

2.2

2.4
Xylene:

o

· o·C

6H4

(CH3)

2

7.8

p

· p·C

6H4

(CH3)

2

7.9

Health and Safety Clearance

Return Authorization Policy

In compliance with Federal OSHA Safety Standard 1910.1200, Hazard Communications “Right to
Know”, Varian is enforcing that standard to preclude the potential health risk to its service person­nel that can occur when receiving, disassembling, or repairing potentially contaminated products.

Returned products not accompanied by this completed certificate will be held until the completed
certificate is received; failure to provide this completed certificate within 30 days of notification
will result in the return of held product(s) unprocessed.

If a product is received at Varian in a contaminated condition, the customer will be held respon­sible for all costs incurred to ensure the safe handling of the product.

Company Name:
__________ Hereby certify that the product(s) listed below have been cleaned of all hazardous

residue and that the residue remaining is of a non-hazardous nature.

__________ Hereby certify that the product(s) listed below have been contaminated by the fol-

lowing toxic or hazardous materials:

RA Number Model Number Serial Number

________________________ ______________________ ______________________

________________________________________ _______________________________ ___________
Authorized Signature Title Date

Note: Varian Service will only accept contaminated Turbo or Mechanical Pumps. All other

products must be decontaminated by the customer before Varian Vacuum Products
Lexington will assign a Return Authorization (RA) number and authorize the return of
the product (refer to the attached Return Authorization Report on the next page).

Note:Varian Vacuum Products Lexington cannot accept any biological hazards,

radioactive material, organic metals, or mercury at its facility.

V arian V acuum Products
21 Hartwell Avenue
Lexington Massachusetts 02421
Telephone [phone]

FAX [phone]

November 1995

Returned Material Report

This report must accompany all products returned for repair, replacement, or warranty evaluation.Full informa­tion regarding reasons for return of the product will expedite repair or adjustment.Please fill in all blanks below
and furnish any other information which will help identify the nature and cause of failure.

Reason for Return (check appropriate box)

❒ Paid Repair ❒ Advance Exchange ❒ Shipping Error ❒ Credit
❒ Warranty Evaluation ❒ Loaner Return ❒ Shipping Damage

Product Information (use separate forms if more than one model no.)

Varian Model No.

_______________________ Serial No.__________________ Quantity ___________________

Part Description

Purchase Information (if product is being returned for warranty evaluation, show your original purchase order
number and date purchased)

Varian Sales Order No.(if available)

________________________ Machine # ___________________________

Original Purchase Order No._________________________ Purchase Order Date _______________________

Company Name ___________________________________________ Contact _______________________________________
Address
City

______________________________________________________________ State _________________ Zip _____________

Telephone
Failure Report (describe in detail suspected cause or nature of malfunction)

Returned Products

All products returned to Varian/VPD Service Operation for warranty evaluation must be sent prepaid and
customer must comply with the warranty replacement and adjustment provision set forth in the warranty.

Ship directly to:Varian Vacuum Products

Vacuum Products Service Center
121 Hartwell Avenue
Lexington, MA 02421

All products sold by Varian and returned by customer are subject to Varian Vacuum Products standard
terms and conditions of sale including, but not limited to, the warranty and damages and liability provi­sions set forth in the warranty.

November 1995

VPD Service Operation