Series 943Cold Cathode Vacuum Gauge SystemThe Series 943 Cold Cathode vacuum gauge system includes the Series 943 digital controller and two cold cathodesensors: the Series 421 sensor for UHV use, or a lower cost Series 423 I-Mag® sensor for OEM or industrial use. TheSeries 943 Cold Cathode vacuum gauge system is designed to be user-friendly and to provide fast, reliable pressuremeasurement from 10-10 to 10-2 Torr.
The 943 digital controller features two standard independent relay set points, which allows you to confidently controlyour process. Adjust the set points from the front panel while viewing the display. Red LEDs indicate set pointactivation status.
The Series 943 displays pressure from 10-10 to 10-2 Torr using a high visibility LED display. Two types of analog outputare standard, for remote monitoring of pressure. An internal converter provides output that allows a simple logconversion from voltage to pressure over the entire operating range. A fast responding, buffered analog output is alsoprovided through the 15 pin accessory connector on the rear panel.
Front panel functions allow the user to disable the high voltage, as well as set a pressure at which the cold cathode willautomatically turn off. This prevents the controller from displaying incorrect readings when the pressure goes abovethe operating range of the sensor.

Product Features• Wide pressure measurement range 10-10 to 10-2 Torr• Digital LED display with set point status indicators• Choice of two cold cathode sensors; Series 421 orSeries 423 I-Mag®
• Fast system control with two set points• Sensor tubes may be mounted in any position withoutaffecting reading• No filaments to burn out• No need to degas the gauge• No adjustment in emission current or filament voltagerequired• Cleaning of sensor is easy with a demountable tube• Sensor tube less susceptible to contamination due toisolated collectorApplicationsThe 943 Cold Cathode vacuum gaugesystem is well-suited for industrial, processand analytical applications includingpressure measurement of high vacuumchambers and control of high vacuumsystems. Areas of applications may includehigh energy physics, analytical instruments,laser production, ion implantation, massspectrometry, or PVD.Cold Cathode Sensors				Using an inverted magnetron design, the 423 I-Mag® and 421sensor can operate at pressures much lower than a traditionalPenning cold cathode sensor — as low as 10-11 Torr with theproper controller. This increased pressure range makes thecold cathode sensors ideal for UHV use.
A unique design feature of the cold cathode sensors is asecond feedthrough for ion collection. In an ordinary singlefeedthrough design, any current leakage between the anodeand ground would result in pressure measurement errors.
Only the ion current from the cathode contributes to ameasurement reading in a dual feedthrough design, making itideal for process monitoring.
With no filament to burn out, both the 423 I-Mag® and 421sensors are not ruined by sudden inrushes of air and areresistant to vibration damage. Additionally, there is no need toadjust the emission current or to degas the gauge, reducingresponse time to pressure changes.

Type ANW 25 KFNW 40 KF23/4” CF, nonrotatable1” Tube1/2” VCR®-F16.72 (171)6.32 (161)6.27 (159)6.22 (158)7.59 (193)Dimensional Drawing - Series 421 Sensor				Note: Unless otherwise specified, dimensions are nominal values in inches(mm referenced).

The 421 sensor should be selected when you want to bakethe sensor to 250°C with the magnet in place. The sensorconnectors need to be removed.
The 423 I-Mag sensor was created to provide a lower costalternative to the 421. The sensor is more compact, lessexpensive and easier to maintain. If bakeout is required, themagnets and sensor connectors can be removed and thesensor can be baked to 400°C.
In addition, MKS provides a variety of customized gauges tosuit specific customer needs. This includes special sensorsfor many semiconductor processes as well as high energyphysics facilities. We have special versions of the 421 that willoperate at 200°C or others that can be used in high radiationenvironments.

Type ANW 25 KFNW 40 KF23/4” CF, rotatable1” Tube3.41 (87)3.41 (87)3.47 (88)3.26 (83)Dimensional Drawing - Series 423 I-Mag® Sensor			Note: Unless otherwise specified, dimensions are nominal values in inches(mm referenced).

Dimensional Drawing - Series 943 Cold Cathode Controller										Note: Unless otherwise specified, dimensions are nominal values in inches (mm referenced).SpecificationsSeries 943 ControllerMeasurement Range						Set Point Range						Operating TemperatureStorage TemperatureRelative HumidityAltitudePower Requirements
			ResolutionSet PointsSet Point ResponseOutput Voltage
			Front Panel Controls
			Display
			Weight		Compliance1.0 x 10-10 to 1.0 x 10-2 Torr									1.3 x 10-10 to 1.3 x 10-2 mbar									1.3 x 10-8 to 1.3 Pa2.0 x 10-9 to 9.0 to 10-3 Torr									2.7 x 10-9 to 1.2 x 10-2 mbar									2.7 x 10-7 to 1.2 Pa5° to 40°C (41° to 104°F)-10° to 55°C (14° to 104°F)80% maximum for temperatures less than 31°C, decreasing linearly to 50% maximum at 40°C2000 m maximum100 to 120 VAC, 50/60 Hz, 9 W								220 to 240 VAC, 50/60 Hz, 9 W1% of indicated decade2 independently set, SPDT contacts, resistive load; 1 A @ 30 VAC or 24 VDC50 msec for pressures >10-8 TorrAnalog: 0 to 9 VDC										Logarithmic Analog: 1 to 9 VDC, 1 V per decadePower on/off; set point and protect view buttons, LED set point indicators, set point and 			protect adjust potentiometers, high voltage on/off/remote toggle switchRed LED, 7 segments digits 14 mm in height, ±60° viewing angle, 2 digits (1 leading) with 		1½ digit signed exponent, Units shown in either Torr, mbar or Pascal, update rate: 250 msec2.5 lbs. (1.1 kg)
CE421 SensorMeasurement Range						Materials Exposed to Vacuum			ReproducibilityCables and ConnectorsBakeout TemperatureOperating TemperatureCalibration GasInstallation OrientationInternal VolumeWeight with CF1.0 x 10-11 to 1.0 x 10-2 Torr 									1.0 x 10-11 to 1.0 x 10-2 mbar									1.0 x 10-9 to 1.0 PaStainless steel, silver-copper brazing alloy, alumina ceramics, aluminum AL 6061, Elgiloy®, 		OFHC® copper5% of reading at constant temperatureCables connected via bayonet and threaded type coaxial connectors250°C connectors off; 125°C connectors on0° to 125°C (32° to 257°F)Air/nitrogen
Any1.8 in.3 (30 cm3) maximum2.8 lbs. (1.3 kg) w/ CF423 I-Mag®
Measurement Range						Materials Exposed to VacuumReproducibilityCables and Connectors
			Bakeout TemperatureOperating TemperatureCalibration GasInstallation OrientationInternal VolumeWeight with CF1.0 x 10-11 to 1.0 x 10-2 Torr									1.0 x 10-11 to 1.0 x 10-2 mbar									1.0 x 10-9 to 1.0 PaStainless steel, 6061 aluminum, Inconel®, glass and alumina ceramic5% of reading at constant temperatureTube Side: molded connector with a positive locking bolt 						Controller Side: bayonet connector and threaded coaxial connectorTo 400°C (752°F) with CF flanges, with magnet and cable removed0° to 70°C (32° to 158°F)Air/nitrogen
Any0.9 in.3 (15 cm3) maximum2.0 lbs (0.8 kg) w/CFOrdering InformationSeries 943 Controller 1,2943-A-120V50-TR-PC943-A-120V60-TR-PC943-A-220V50-TR-PC943-A-220V60-TR-PC943-A-120V50-MB-PC943-A-120V60-MB-PC943-A-220V50-MB-PC943-A-220V60-MB-PC943-A-120V50-PA-PC943-A-120V60-PA-PC943-A-220V50-PA-PC943-A-220V60-PA-PCSeries 943 Controller, Torr readout, 50 Hz, 100-120 volts					Series 943 Controller, Torr readout, 60 Hz, 100-120 volts				Series 943 Controller, Torr readout, 50 Hz, 220-240 volts				Series 943 Controller, Torr readout, 60 Hz, 220-240 volts					Series 943 Controller, mbar readout, 50 Hz, 100-120 volts					Series 943 Controller, mbar readout, 60 Hz, 100-120 volts					Series 943 Controller, mbar readout, 50 Hz, 220-240 volts					Series 943 Controller, mbar readout, 60 Hz, 220-240 volts					Series 943 Controller, Pascal readout, 50 Hz, 100-120 volts					Series 943 Controller, Pascal readout, 60 Hz, 100-120 volts				Series 943 Controller, Pascal readout, 50 Hz, 220-240 volts				Series 943 Controller, Pascal readout, 60 Hz, 220-240 volts423 I-Mag® Cold Cathode Sensor104230004104230001104230002104230003423 I-Mag Cold Cathode Sensor, NW 25 KF						423 I-Mag Cold Cathode Sensor, NW 40 KF						423 I-Mag Cold Cathode Sensor, 2 3/4" CF						423 I-Mag Cold Cathode Sensor, 1" Tube421 Cold Cathode Sensor104210004104210001104210002104210003104210005421 Cold Cathode Sensor, NW 25 KF								421 Cold Cathode Sensor, NW 40 KF								421 Cold Cathode Sensor, 2 3/4" CF 							421 Cold Cathode Sensor, 1" Tube							421 Cold Cathode Sensor, 8 VCR®-F3423 I-Mag® Cold Cathode Cables1000025052 ft. (0.6 m)																		10000787310 ft. (3.0 m)										10000787425 ft. (7.6 m)									10000239550 ft. (15 m)									100008759Custom Cable421 Cold Cathode Cables10000617110000617210000617310000617410000617510 ft. (3.0 m)										25 ft. (7.6 m)									50 ft. (15.2 m)									100 ft. (30.5 m)									Custom CableAccessories103150001100005087100005021100006734100002353100005279100009887Power Cord, 115 VAC								Series 943 Output Connector Kit							Mounting Hardware									Rebuild Kit for Series 421 Cold Cathode Sensor (6 bolt, 1/4-28)					Rebuild Kit for Series 423 I-Mag Sensor							Wrench for Series 421 Sensor Rebuild Kit						Series 943 Cold Cathode ManualIncludes controller, power cord, manual and output connector.
Controller also available without power cords. NA is inserted into the part number instead of PC3VCR®-compatible parts may be used.
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Specifications are subject to change without notice.

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.
mksinst™ is a trademark and I-Mag® is a registered trademark of MKS Instruments, Inc. Viton® is a registered trademark of E.I. Dupont Co. Inc. Elgiloy® is a registeredtrademark of Elgiloy Specialty Metals, Elgin, IL. OFHC® is a registered trademark of AMAX, Inc. U.S. Patent # 6,756,785. Foreign patents pending.