Advanced Vacuum Measurement Solutions
Product Selection Guide
Users worldwide turn to MKS Instruments for reliable, precise and dependable vacuum
measurement technology. MKS vacuum gauges, electronics, modular vacuum products, andtailored solutions provide the flexibility, reliability, and precise performance that are essential foryour application. The MKS line of vacuum measurement products, that measure from 10-11 to1500 Torr, offers the best and broadest range of vacuum and pressure measurement solutions.
Our vacuum gauges, transducers, sensors and controllers are based on multiple pressure
measurement technologies including Convectron®, Micro-Ion®, MicroPirani™, Piezo hot and cold
cathode, Stabil-Ion®, and MEMS-based multi-sensor technology. These vacuum gauge andtransducer products are used individually or integrated in combination, providing a wide variety
of pressure and vacuum measurement options in terms of gas independence, covered pressure
ranges and tolerance to aggressive gases.
If your vacuum systems are used for semiconductor process
tools, analytical instruments, educational or governmental
research, or industrial processes, you face an assortment ofchallenges. MKS is the solution—providing accuracy, stability
and dependability to improve the quality and productivity ofyour vacuum processes.

Vacuum Measurement Products• Stabil-Ion Gauges, Controllers and Spinning Rotor Gauge• Micro-Ion Gauges, Controllers and Transducers• Bayard-Alpert Vacuum Gauges and Controllers• Cold Cathode Gauges and Transducers• Mini-Convectron, Convectron Gauges, Controllers 		
and Transducers• MicroPirani and Piezo Transducers• Combination Gauge/System Controllers• Vacuum Quality Monitor (VQM) Systems

Key Benefits• Precise performance• Integrated technology providing a wide
variety of measurement• Ideal for semiconductor, analytical,
research and industrial applications

Stabil-Ion® Gauges, Controllers and Spinning Rotor Gauge
Stabil-Ion® products are the most accurate products in Bayard-Alpert (B-A) hot cathode gauge technology and electronics. They
are used in vacuum research and manufacturing processes where accurate and repeatable vacuum pressure indication is critical.
Stabil-Ion gauges are an all-metal B-A style gauge that was developed to provide and maintain long-term accuracy over thelife of the product. Many patented design features have removed the inaccuracies and pressure indication changes that occur
with typical B-A gauge products. The Spinning Rotor Gauge (SRG) line is a high-vacuum gauge that operates by measuring
the amount of viscous drag on a magnetically-levitated spinning ball, which is directly related to the number of molecules in thechamber. The SRG is an industry calibration standard, often used in a metrology department.

Series 360 and 370 Stabil-Ion® Gauges• All-metal with precision-wound, stress-relieved anode retains shape for the life of the gauge• Rugged stainless steel construction prevents grid and filament damage• Tensioned dual filaments stay precisely positioned to maintain stability and calibration• Vacuum-fired components prevent contamination and speed system pumpdown• Unique design and precise manufacturing processes assure long-term, accurate 					 measurement
Series 370 Stabil-Ion® Vacuum Measurement System• Rack-mount controller for Stabil-Ion and Convectron is noise-immune• Provides accurate pressure measurement from the 10-11 Torr range• Dual convectron gauge option extends pressure measurement to atmosphere and allows
automatic turn on/turn off of the Stabil-Ion gauge• Simultaneous 3-digit display pressure for three gauges• RS-232 and RS-485 computer interface options

Spinning Rotor Gauge System• Transfer standard for vacuum measurement• Recognized transfer standard for calibration in 10-2 to 10-7 Torr (mbar) vacuum range, 				 DKD traceable• Insensitive to ionization effects from other vacuum gauges• Long term stability• Guaranteed precision from 5x10-7 to 1x10-2 mbar (Torr)

Micro-Ion® Gauges, Controllers and Transducers
The Micro-Ion® gauge is the world’s smallest B-A style gauge in an all-metal, rugged enclosure. Micro-Ion gauges are compact,
reliable, cost-effective, and measure a wide range of vacuum pressure. Micro-Ion modules are available with dozens of different
options and capabilities to meet any need for accurate pressure measurement from 10-9 Torr to atmosphere.

Series 355 Miniature Bayard-Alpert Gauges• Rugged all-metal enclosure prevents grid and filament damage and eliminates the risk of 				 glass breakage• Measures pressure from 5x10-10 to 5x10-2 Torr
• Less than 5% of the volume of conventional glass B-A gauges• Only 8% of the power consumption of typical glass or nude B-A gauges• Dual tungsten or burn-out resistant yttria-coated iridium filaments provide long gauge life
Series 358 Micro-Ion® Vacuum Gauge Controller• Compact, reliable, rack-mount controller for optimum Micro-Ion gauge performance• Vacuum pressure measurement from 10-10 Torr range• Dual Convectron gauge option extends pressure measurement to atmosphere and allows
automatic turn on/turn off of the Micro-Ion gauge• Process control options with up to six set point relays and manual override• RS-232 or RS-485 computer interface options

Series 355, 392, 390 Micro-Ion® Modules and Transducers• Series 355: Micro-Ion transducer provides vacuum pressure measurement from 					 5x10-9 Torr to 10-2 Torr
• Series 392: Combines Micro-Ion and Conductron sensors to provide measurement		
		 from 10-9 Torr to atmosphere• Series 390: Combines Micro-Ion, Conductron and Piezo resistive sensors to provide 				 measurement from 10-9 Torr to atmosphere, along with gas independent atmospheric 				 pressure indication

Bayard-Alpert Vacuum Gauges and Controllers
Classic glass and nude B-A gauges provide good vacuum measurement at an economical cost. Nude B-A gauges for use in
UHV systems are commonly used with the Series 307 and the Series 350 UHV vacuum gauge controller to measure pressures
down to the 10-11 Torr range. The Series 307 and 350 controllers are easy to use and offer optional pressure set points that allow
control of various system functions such as switching valves, interlocks, alarms, etc.
Series 274 Glass and Nude B-A Gauges• Industry standard electrode voltages, wide range electron emission currents 10 µA to 10 mA• Available with burn-out resistant filaments and standard vacuum connections• Can be degassed by electron bombardment (EB); some can be degassed by resistance (I2R)• Provides good vacuum pressure measurement from 1x10-9 to <1x10-3 for economical cost
• Available in tubulated (glass) or nude models
Series 307 and 350 UHV Controllers• Lower measurement limit of <2x10-11 Torr or the X-ray limit of a B-A gauge with 10 mA 				 emission and gauge sensitivity of 25 Torr
• Upper measurement limit of 1x10-2 Torr with 0.1 mA emission and gauge sensitivity of 				 25 Torr
• Controlled, adjustable emission current from 0.01 to 10 mA• Logarithmic analog output of 1 V/decade, 0 to 10 VDC• Up to 6-channel process set points with SPDT relays that can be set over the entire pressure		 range with manual override switches• RS-232 and RS-485 interfaces

Cold Cathode Gauges and Transducers
MKS Instruments offers a wide range of cold cathode products. The 970B Series is a family of compact, low cost, generalpurpose transducers that utilize from one to three sensors — cold cathode, MicroPirani™ and Piezo technologies. Combining
these sensing technologies enables a wide measurement range from 10-8 Torr to atmosphere. In addition to its small size, broad
range and lower cost, the 970B Series can be operated via digital communication or as an autonomous analog unit. The family
comprises of three transducer models, the 971B UniMag (cold cathode), 972B DualMag (MicroPirani/cold cathode) and the 974B
QuadMag (Piezo/MicroPirani/cold cathode). Options include a local display and set point relays. The Series 500 CCG provides
unsurpassed accuracy for a cold cathode gauge. Modern design techniques together with microprocessor monitoring andcontrol deliver long life, high accuracy and predictive and easy maintenance.
Series 970B Cold Cathode Transducer Family• Wide measurement range 10-8 to 1000 Torr
• Low CCG turn on pressure (5x10-4 Torr) for longer lifetime• Small footprint design provides a compact solution saving tool real estate• User-serviceable anode module designed to decrease downtime to save external repair costs• All transducers include both analog and digital communication for ease of operation• Simplified interface via single analog output combining individual sensor measurements• Series 972B includes EtherCAT® user interface*
Series 500 Cold Cathode Gauge• Wide measurement range from 10-10 to 10-2 Torr
• Calibrated gauge option provides ±10% accuracy• Predictive and easy maintenance• USB interface and GP connect software to setup and monitor gauge operation and usage• Baffle keeps sputtered material from entering your process chamber

422, 423 & 431 I-Mag® Cold Cathode Vacuum Sensors• Wide measurement range from 10-11 to 10-2 Torr
• Dual feedthrough ion collection for increased accuracy• Optional radiation resistance and high temperature versions• Cleaning of sensor is easy with a demountable tube

* For additional information on EtherCAT models, see the MKS EtherCAT Selection Guide, highlighting our comprehensive 		
portfolio of EtherCAT-compatible products.

Vacuum Gauge Transducers & Modules

10-11

10-10

10-9

10-8

10-7

PRESSURE MEASUREMENT RANGE

10-6

10-5

10-4

MicroPirani &differential Piezo for
fast, accurate, gasindependent atmosphericmeasurement on
loadlocks

901P

MicroPirani™/
Piezo Loadlock

10-3

10-2

10-1

1

10

100

1000

HEAT-LOSS SENSOR

ABSOLUTE / DIFFERENTIAL
DIAPHRAGM SENSOR

HEAT-LOSS SENSOR

ABSOLUTE
DIAPHRAGM SENSOR

MEMS based
Piezo sensor for
gas-independentmeasurement

902B

Absolute Piezo

MicroPirani & Absolute
Piezo for increased
accuracy & gasindependentmeasurement at higher
pressures

910

DualTrans™
MicroPirani/
Absolute Piezo

MicroPirani provides
measurement 1 – 2
decades lower thanstandard Pirani gauges

925

MicroPirani

275

Mini-Convectron®

355

Micro-Ion®

Convection enhanced
Pirani is factory
calibrated

Micro-Ion transducer
provides high sensitivity
for low noise & higher
accuracy
Micro-Ion, Conductron,and two Piezo sensors
provide extended range& gas-independent highpressure measurement

HOT CATHODE ION SENSOR

392

Micro-Ion & Conductron
are combined for fullrange measurement

HOT CATHODE ION SENSOR

971B

Stand-alone compact
cold cathode972B

Combination cold
cathode, MicroPirani

COLD CATHODE ION SENSOR

974B

Combination cold
cathode, MicroPirani,differential Piezo

COLD CATHODE ION SENSOR

500

Double inverted
magnetron provides
unprecedented accuracy& predictive maintenance390

Micro-Ion ATM

Micro-Ion Plus
UniMag™
DualMag™
QuadMag™

Cold Cathode
Gauge

Vacuum Quality Monitor (VQM®) Systems

HEAT-LOSS SENSOR

HEAT-LOSS SENSOR

ABSOLUTE / DIFFERENTIAL
DIAPHRAGM SENSOR

HEAT-LOSS SENSOROPERATING PRESSURE RANGE
10-11

World’s fastest, lowest
power mass spectrometer;full data collection,
spectral deconvolution& data logging

835

Extends pressure rangeof VQM for processmonitoring & control
applications up to 3 Torr

VQM Differential
Pump System

ABSOLUTE / DIFFERENTIAL
DIAPHRAGM SENSORCOLD CATHODE ION SENSOR

835

Vacuum Quality
Monitor (VQM)
SystemHEAT-LOSS SENSOR

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

1

10

100

1000

PRESSURE MEASUREMENT RANGE

Vacuum Gauges

10-11

274

Glass/Nude
Bayard-Alpert
Ionization

275

Convectron
Pirani®

355

Micro-Ion®
Bayard-Alpert

370

Stabil-Ion
Bayard-Alpert®

423, 431

I-Mag® Cold
Cathode

10-10

10-9

10-8

10-7

Pressure measurement
for an economical cost,
available with burn-out
resistant filaments &standard connections

10-6

10-5

10-4

10-3

10-2

10-1

1

10

100

1000

10-1

1

10

100

1000

GLASS

NUDE

Convection-enhanced
Pirani gauge provides
high accuracy &repeatability
Smallest Bayard-Alpert
style, more rugged withwide range, generates
less heat, greater burnout
resistance
Most accurate BayardAlpert features an all
metal gauge tube forstability & long-term
repeatability
Based on inverted
magnetron design withunique dual feedthroughfor increased range &accuracy
PRESSURE MEASUREMENT RANGE

Vacuum Gauge Controllers

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

1 OR 2 BAYARD-ALPERT GAUGES

307

Bayard-Alpert

Bayard-Alpert full rack
controller with optional
two Convectron gauges

OPTIONAL: UHV BAYARD-ALPERT GAUGEOPTIONAL: 2 CONVECTRON GAUGES

350

Bayard-Alpert
UHV

358

Micro-Ion half rack with
optional two Convectrons

Micro-Ion®

Dual (sequential)
Stabil-Ion full rack
controller w/optional two
Convectrons provides
high accuracy &repeatable measurement

370

Stabil-Ion®

SRG

Spinning Rotor
Gauge

475

Convectron

®

937B

Vacuum Gauge
Controller

946

Vacuum System
Controller

PDR900

Bayard-Alpert UHV half
rack controller with
optional two Convectron
gaugesFor Series 900
Transducers

1 UHV BAYARD-ALPERT GAUGEOPTIONAL: 2 CONVECTRON GAUGES

1 MICRO-ION GAUGEOPTIONAL: 2 CONVECTRON GAUGES

1 OR 2 STABIL-ION GAUGEOPTIONAL: 2 CONVECTRON GAUGESMetrology transfer
standard

Single Convectron
controller includes preprogrammed gas curves
Supports a wide rangeof sensor technologies
including cold & hotcathode, Pirani, Piezo &Baratron® gauges
Versatile half-rackcontroller provide
pressure measurement
along with flow &pressure control
Stand-alone, single
channel, or tool for
configuration & foradvanced system
diagnostics

1 CONVECTRON GAUGECOLD CATHODE SENSOR
HEAT-LOSS SENSORCAPACITANCE DIAPHRAGM GAUGE AND PIEZO DIAPHRAGM GAUGEFLOW RANGE - 2.0 x 10-3 SCCM to 1,000 SLM

PRESSURE CONTROL RANGE

Mini-Convectron®, Convectron® Gauges, Controllers and Transducers
Convectron gauges have been the world-standard convection-enhanced pirani gauge for over three decades and are usedin thousands of vacuum processes to accurately measure pressure from 10-4 Torr to atmosphere. Every Convectron gauge
is individually calibrated before shipping from the factory. The Series 475 Convectron gauge controller incorporates the latest
technological advances in electronics and design. Mini-Convectron modules combine the Convectron gauge with electronics
in a compact modular design and are available with dozens of different options and capabilities to meet any need for accuratepressure measurement from 10-3 Torr to atmosphere.
Series 275 Mini-Convectron® Transducers• DeviceNet digital interface facilitates easy system integration• Wide range pressure measurement from 10-3 Torr (10-3 mbar, 10-1 Pa) to atmosphere• Individually calibrated gauges assure highest measurement performance• Compact, rugged, RF and noise-immune module• Two software-controlled set point relays provide safety interlocking
Series 275 Convectron® Vacuum Gauge• Wide range vacuum pressure measurement from 1x10-4 Torr to atmosphere• Individually calibrated gauges assure the highest measurement performance• Easy installation in space-restricted locations• Wide selection of vacuum fittings simplifies installation on your vacuum system• Rugged construction

Series 475 Convectron® Gauge Controller• Wide range vacuum pressure measurement from 1x10-4 Torr to atmosphere• Individually calibrated gauges assure the highest measurement performance• Easy installation in space-restricted locations• Wide selection of vacuum fittings simplifies installation on your vacuum system• Rugged construction

MicroPirani™ and Piezo Transducers
The Series 900 vacuum transducers are microprocessor-based, stand-alone gauges that offer ultra compact design and awide pressure measurement range. Designed for system integration, the Series 900 transducers offer both analog and digitalcommunication and incorporate MEMS-based (Micro Electro-Mechanical Systems) technologies including MicroPirani™ and Piezo
sensors. These transducers are mountable in any orientation without loss of accuracy for ease of installation.
Series 901P MicroPirani™/Piezo Loadlock Transducer• Accurate absolute measurement from 10-5 to 1000 Torr, gas independent (60 to 1000 Torr)• Fast, accurate, and repeatable pressure measurements reduce process cycle time
• Ease of integration via EtherCAT, RS-232 or RS-485 and analog user interfaces*

Series 902B Absolute Piezo Transducer• Measurement range of 0.1 to 1000 Torr Full Scale• Low cost transducer alternative to more expensive conventional transducers• Gas independent pressure measurement for accurate, total pressure measurement• Sensor is suitable for harsh processes due to robust design and stainless steel construction• Solid state Piezo sensor resistant to damage from air inrush and vibrations• Ease of integration via RS-232 or RS-485 and analog user interfaces

Series 910 DualTrans™ MicroPirani™/Absolute Piezo Transducer• Two sensors in a single transducer for space savings and wide measurement range• Absolute pressure measurement from 10-5 to 1500 Torr
• Gas independent absolute pressure measurement from 11 to 1500 Torr
• Fast, accurate and repeatable pressure measurements reduce process cycle time

Series 925 MicroPirani™ Transducer• Measurement range from 10-5 Torr to atmosphere, 2 decades beyond a standard Pirani• High accuracy for improved process control• Pre-programmed gas curves for N2, Ar, He, H2, H2O, Xe and CO2• Ease of integration via EtherCAT, RS-232 or RS-485 and analog user interfaces** For additional information on EtherCAT models, see the MKS EtherCAT Selection Guide, highlighting our comprehensive 		
portfolio of EtherCAT-compatible products.

Combination Gauge/System Controllers
MKS offers highly flexible vacuum gauge controllers that enable a wide range of gauging technologies, tailoring the system toeach individual application. These versatile vacuum controllers provide power and simultaneous readouts for up to six different
vacuum gauges and/or mass flow controllers, with options for controlling pressure, calibration, and system diagnostics. These
instruments set new standards in vacuum gauge control for OEM applications.
Series 937B Digital Combination Vacuum Gauge System					• Provides simultaneous readout for a combination of up to six vacuum gauges• Wide measurement range of 10-11 to 10,000 Torr
• Intuitive menu for ease of setup• Large easy to read backlit display• User-configurable for units of pressure in Torr, millibar, Pascal, or microns• Configurable for up to six heated MKS Baratron® capacitance manometers• Twelve independent relay set points for improved process control with variable hysteresis
Series 946 Vacuum System Controller• Simultaneous control and readout for up to six vacuum gauges and/or six mass flow 				 controllers for ultimate versatility• Provides pressure measurement, flow, valve, and pressure control• Closed-loop pressure control option for use with MKS valves eliminates the need for 				 separate pressure control electronics• RS-232/485 computer control standard in all configurations for ease of system interfacing
Series PDR900 Controller• Single channel controller for use with 900 Series transducers• LCD menu display for easy user interface• Easy to read 5 digit LED display• Three high power set point relays for process control• Auto setup enables plug and play functionality• Leak detection tool for system diagnostics• Data logging tool for process monitoring• Simplified setup and configuration of transducer parameters• Front panel indicators provide clear, concise overview of set point relay status

Comparison Chart
307

350

358

370

475

Cold Cathode Gauge

946

Y(3)

Y(3)

Y(6)

Y(6)

Y(3)*

Y(3)*

Y(6)

Y(6)

Convectron Gauge

Y(2)

Y(2)

B-A Glass or Nude Gauge

Y(2)

Y(1)

Nude UHV Ionization Gauge

Y(2)

Y(1)

Y(2)

Y(1)

Y(2)

Y(1)

Y(1)

For Use with Series 900 Transducers

Y(1)Micro-Ion Gauge

Baratron® Capacitance
Manometer

Y(6)Mass Flow Controllers

Features

PDR900Y(2)Stabil-Ion UHV Gauge

Gauges and Transducers

937B

Adjustable Process Control
Relays

Y(6)

Y(6)

Y(6)

Y(6)

Y(2)

Y(12)

Y(12)

Y(3)

Analog Output(s)

Y

Y

Y

Y

Y

Y

Y

Y

RS-232 Interface

Y

Y

Y

Y

Y

Y

Y

Y

RS-485 Interface

Y

Y

Y

Y

Y

Y

Y

IEEE 488 Interface

Y

Profibus Interface
Y= Yes Y + (#) = possible number of gauges or set points.
* Low power nude gauge only.

YYVacuum Quality Monitor (VQM®) Systems
Vacuum Quality Monitor systems are used by research labs and production facilities to monitor the quality and compositionof the gases in their vacuum system. Typical usage includes system baselining, post chamber PM verification, leak detection,
contamination checking, and monitoring the overall quality of the vacuum in the system. The sensor used in the VQM system isan auto-resonant ion trap mass spectrometer gauge – the newest and fastest technology in use today.
Series 835 VQM® Mass Spectrometer System• 1-145 amu total and partial measurement information in 85 ms, or 1-300 amu in 120 ms• Instant access to 10 most prevalent gases in normalized, percentage and absolute values,		 total pressure and partial pressure trend graphs• Accurate hydrogen and helium measurements (no zero blast)• Easy single-gas calibration using a gas already in your vacuum system• Low power requirement - only 15 W
• Remotely mounted gauge using a 1-meter to 50-meter long cable
Series 835 VQM® Differential Pump System• All the benefits of the 835 VQM with an extended operating range from 5x10-9 to 3 Torr
• Gate valve with orifice designed for operation at base and process pressures• Scan range from 1-145 amu or optionally 1-300 amu• Process control through software API, LabVIEW VIs, or dedicated output

AVMS Product Guide_11/19©2019 MKS Instruments, Inc.

www.MKSINST.com+1-978-645-5500 I +1-800-227-8766

MKS products provided subject to the US Export Regulations.
Export, re-export, diversion or transfer contrary to US law (and local country law) is prohibited.
Specifications are subject to change without notice.
Granville-Phillips®, Stabil-Ion®, Micro-Ion®, Convectron®, Mini-Convectron®, and VQM® are registeredtrademarks and mksinst™, MicroPirani™ and Vacuum Quality Monitor™ are trademarks of MKS Instruments, Inc.
DeviceNet™ is a trademark of Open DeviceNet Vendor Association. EtherCAT® is a registered trademark and patented
technology, licensed by Beckhoff Automation GmbH, Germany.