AML NGC3 User manual

NGC3 Ion Gauge Controller
UHV Dual Bayard-Alpert Ion Gauge Controller
USER MANUAL
ISSUE 20200326
For use with firmware version 7.x.x

1. Introduction .................................................................................................................................................................... 5
1.1. Scope of this manual.................................................................................................................................................................................................................5
2. Technical data................................................................................................................................................................. 6
2.1. Mechanical Data .........................................................................................................................................................................................................................6
2.2. Electrical Supply..........................................................................................................................................................................................................................6
2.3. Environment.................................................................................................................................................................................................................................6
2.4. Electrometer.................................................................................................................................................................................................................................6
2.5. Ion Gauge......................................................................................................................................................................................................................................7
2.6. Pirani Gauge.................................................................................................................................................................................................................................7
2.7. Active Gauge................................................................................................................................................................................................................................7
2.8. Process trips .................................................................................................................................................................................................................................7
2.9. Bake-out ........................................................................................................................................................................................................................................7
2.10. Communications.........................................................................................................................................................................................................................7
3. Warnings and safety ...................................................................................................................................................... 8
4. Installation....................................................................................................................................................................... 9
4.1. Instrument installation..............................................................................................................................................................................................................9
4.2. Ion Gauge-head installation..................................................................................................................................................................................................11
5. Front panel .................................................................................................................................................................... 12
6. Setup .............................................................................................................................................................................. 13
6.1. Switching on...............................................................................................................................................................................................................................13
6.2. Setup, General description ....................................................................................................................................................................................................13
Password/Units..........................................................................................................................................................................................................................13
Ion Gauge Mode.......................................................................................................................................................................................................................14
Gauges .........................................................................................................................................................................................................................................17
Relay assignment......................................................................................................................................................................................................................19
Bake...............................................................................................................................................................................................................................................19
Degas............................................................................................................................................................................................................................................20
7. Operation....................................................................................................................................................................... 21
7.1. Use of the Function Switch in the operating positions ................................................................................................................................................21
7.2. Relay trip levels .........................................................................................................................................................................................................................21
7.3. Display sequence when the function switch is in the OFF position .........................................................................................................................22
Pirani.............................................................................................................................................................................................................................................22
Active Gauge..............................................................................................................................................................................................................................22
IG Sensitivity...............................................................................................................................................................................................................................22
Leak Detector.............................................................................................................................................................................................................................23
Temperature...............................................................................................................................................................................................................................23
Instrument ID.............................................................................................................................................................................................................................23
8. Ion Gauge operation.................................................................................................................................................... 24
8.1. Display sequence when Ion Gauges are in emission ....................................................................................................................................................24
Starting the Ion Gauge............................................................................................................................................................................................................24
Manual Emission Change.......................................................................................................................................................................................................25
8.2. Changing Ion Gauge emission .............................................................................................................................................................................................25
8.3. Prompted emission change ..................................................................................................................................................................................................25
9. Degassing ...................................................................................................................................................................... 26
Manual Degas............................................................................................................................................................................................................................27
Programmed Degas.................................................................................................................................................................................................................27
Quick Degas ...............................................................................................................................................................................................................................27
10. Bake................................................................................................................................................................................ 28
11. Recorder Output........................................................................................................................................................... 29
12. External inhibit ............................................................................................................................................................. 29

13. Windows Software ....................................................................................................................................................... 30
14. Remote operation ........................................................................................................................................................ 30
14.1. Introduction................................................................................................................................................................................................................................30
14.2. Interface protocol.....................................................................................................................................................................................................................30
14.3. Local/remote control...............................................................................................................................................................................................................30
14.4. Host Computer Commands ..................................................................................................................................................................................................31
14.5. NGC3 Response ........................................................................................................................................................................................................................31
14.6. Timing of Next Command .....................................................................................................................................................................................................31
14.7. State & Error byte coding......................................................................................................................................................................................................31
14.8. Host Computer Command Characters ..............................................................................................................................................................................32
14.9. <status> Status report............................................................................................................................................................................................................33
15. Troubleshooting ........................................................................................................................................................... 34
15.1. Fan slow / failed........................................................................................................................................................................................................................34
15.2. Temperature...............................................................................................................................................................................................................................34
15.3. Emission Fault............................................................................................................................................................................................................................34
15.4. IG Fil O/C.....................................................................................................................................................................................................................................34
15.5. Password forgotten?................................................................................................................................................................................................................34
15.6. Ion Gauge connections...........................................................................................................................................................................................................35
16. Assistance ...................................................................................................................................................................... 35
Appendix A Gauge Principles.................................................................................................................................... 36
A.1 Ionisation Gauges.....................................................................................................................................................................................................................36
A.2 Pirani Gauges.............................................................................................................................................................................................................................36
A.3 Capacitance manometers ......................................................................................................................................................................................................36

© Arun Microelectronics Ltd 2020. All rights reserved Page 5
1. Introduction
The NGC3 process controller is a high-accuracy Bayard-Alpert (BA) Ion Gauge controller that offers integrated pressure
measurement and process control. The controller operates from electrical supply voltages in the range 100 to 240 volts and
frequencies of 48 to 65 hertz.
The controller may be used with UHV Ion Gauges incorporating tungsten or coated iridium filaments. The controller can
operate two Ion Gauges sequentially, two AML Pirani Gauges and one Active Gauge-head via a standard RJ45 jack.
Four power relays for process control are provided as is an internal thermocouple amplifier for bakeout control.
1.1. Scope of this manual
This manual provides installation, operation and maintenance instructions for the Arun Microelectronics Ltd Ion Gauge
Controller model NGC3. Please read this manual before attempting to install and operate the controller.
This manual contains essential safety information which supplements the safety features of the controller. Safety
procedures are highlighted as WARNING instructions by the symbol below. Failure to observe the instructions could result
in injury or death to persons.

© Arun Microelectronics Ltd 2020. All rights reserved Page 6
2. Technical data
2.1. Mechanical Data
Dimensions
Width: 19″full-width rack (482.6 mm)
Height: 1U (44.45 mm)
Depth: 270 mm, excluding connectors
Weight
2.7 kg
2.2. Electrical Supply
Supply voltage
100 to 240 volts nominal at 48 to 65 hertz, auto-adjusting
Power consumption
Less than 20 W idle
90 W maximum
Fuse
2.0 A, 250 V (T), 5 x 20 mm
Supply socket
IEC 320-C14
Overvoltage category
II
Protection class
1
2.3. Environment
Operating temperature
5°C to 35°C for specified performance
Operation is inhibited at greater than 40°C
Storage temperature
-10°C to 70°C
Relative humidity (non-condensing)
80 % for temperatures up to 31 °C, decreasing linearly to 50 % at 40 °C
Maximum operating altitude
2000 m
Pollution category –EN61010
1
Ingress protection
IP20
2.4. Electrometer
Logarithmic conformance1
Range
21°C
+5°C to +35°C
1 mA to 350 pA
<1%
<1%
<350 pA to 10 pA
<1%
<4%
<10 pA to 2 pA
<10%
<20%
1
Some reduction in performance may occur at 30 MHz to 1 GHz at high RF field strengths

© Arun Microelectronics Ltd 2020. All rights reserved Page 7
2.5. Ion Gauge
Suitable type
UHV Bayard-Alpert Gauges with coiled filaments
Range
1 x 10-3 to below 3 x 10-11 mBar. Dependant on gauge-head
Grid
+200 Vdc (+500 V at 60 mA in Degas)
Filament
Tungsten: ≤12 V at ≤4.2 A
Coated iridium: ≤12 V at ≤2.6 A
Filament power limited to >30 W
Filament bias: +50 V
Collector
0 V (virtual earth)
Emission current
Soft-start emission control at 0.5 mA or 5 mA
Sensitivity adjustment
1 mBar-1 to 140 mBar-1
2.6. Pirani Gauge
Suitable type
Constant-voltage, half bridge. Calibration at connector
Range
1 x 10-3 mBar to 200 mBar
2.7. Active Gauge
Suitable type
Self-powered or active gauge with +10 V full-scale output.
Format selectable between linear (1, 10, 100, 1000 mBar or Torr full
scale) or log (1 V/decade, 0.5 V at 1E-6 mBar)
The instrument provides a regulated +24 Vdc supply, 1.0 W maximum,
protected by a 50 mA self-resetting fuse to power a connected active
gauge.
2.8. Process trips
Relays
4 x single-pole, change-over. 5 A at 240 V maximum
Assignment
Independently assignable to any gauge
2.9. Bake-out
Thermocouple type
Mineral-insulated K-type with miniature flat-pin connector
Programme
Settable bake temperature (50°C to 250°C), bake time (1 hour to 90
hours) and overpressure limit
2.10. Communications
Interface
RS232C
Settings
1200, 2400, 4800 or 9600 (Default) baud,
8 data bits, 1 stop bit, no parity, no handshaking

© Arun Microelectronics Ltd 2020. All rights reserved Page 8
3. Warnings and safety
WARNING –Safe operation of Ion Gauges requires grounding of all exposed
conductors of the vacuum system, gauges and controller. LETHAL VOLTAGES may be
established under some operating conditions unless correct grounding is provided. All
exposed and isolated metal parts should be reliably grounded to a common system
earth point via 4 mm2or thicker copper wire/braid, the integrity of which should be
checked regularly. No ferrite components should be installed.
High voltages are present within the instrument when operating and for some seconds after switching
off. Remove the mains lead before removing the cover for any reason.
Ensure that maintenance is carried out only by suitably trained personnel.
Voltages up to 500 V in degas and 200 V in normal operation are present on the IG cable when the IG is
on. Voltages up to 600 V are present within the instrument.
•This manual must be consulted in all cases where the warning symbol (shown above, left) appears on the
instrument.
•The safety of any system incorporating the instrument is the responsibility of the assembler of the system.
•Use the instrument only as specified in this manual, or the protection provided by the instrument might be
impaired.
•The mains lead must be adequately rated for the instrument.
Instruments are shipped with password protection disabled. If you set a password you must record what it is.
The conditions set at manufacture assume that you do not require any interlocks and that the Ion Gauges have a tungsten
filament. You may fuse coated Ion Gauge filaments if you do not set up the instrument appropriately.
Allow several minutes for Pirani Gauges to reach operating temperature after switching on before using them for interlock,
autostart or process control.
Two fans are used sequentially for cooling. Orange status LEDs on the front panel indicate which fan is being used. If a fan
fails a message is displayed at the time of failure and the LED for that fan flashes thereafter. Operation with only one fan is
permissible but the faulty fan should be replaced as soon as possible. If the remaining fan fails, operation of the Ion
Gauges will be disabled. Replacement fans must conform to the specification printed on the rear panel and are available
from AML.
Discharges from X-ray power supplies and other high-voltage and high-energy sources (which are commonly used in
vacuum systems) into the Ion Gauge may damage the instrument. Such damage is not covered by the warranty. Discharge
damage will be minimised by decreasing the impedance of the strap/cable from the earth stud on the instrument to the
vacuum system earth distribution point. This connection may also be essential for operator safety: follow the safety
instructions and recommendations of the supplier of any high-voltage equipment used in the vacuum system.

© Arun Microelectronics Ltd 2020. All rights reserved Page 9
4. Installation
Checks on receipt of the instrument
On receipt of the instrument remove all packing material and check that all items on the shipping list have been received.
Report any damage or shortages to the Company or the Distributor who supplied the instrument. The packing material has
been specifically designed to protect the instrument and should be retained for possible future use.
4.1. Instrument installation
Mounting
The instrument is suitable for mounting in a standard 19″rack and occupies 1U (1.75″, 44.45 mm) of the rack. The
mounting holes in the front panel are intended for retaining the instrument in the rack and will not support its weight.
Additional support is required toward the rear and various arrangements are provided by rack manufacturers for this
purpose.
Cleaning
If the instrument requires cleaning, wipe it down with a cloth slightly dampened with water or a mild detergent.
Ventilation
The instrument is forced air ventilated through grilles on the sides and a vent in the rear panel. Mount it in a location where
there is an adequate supply of air as close as possible to cool room ambient temperature. The instrument is tolerant of
and is compensated for operation at elevated ambient temperatures up to 40°C. Long term accuracy and reliability will be
enhanced by operation at the lowest possible temperature, within the operating temperature range. If there are other
instruments in the rack which generate significant amounts of waste heat, try to ensure that this is deflected away from this
instrument.
Line Power Connection
The NGC3 operates from a 100 to 240 volts nominal AC power source having a line frequency of 48 to 65 Hz. Use a three-
wire power cord to connect to a properly grounded wall outlet.
Line Fuse
There is a line fuse (Rating: 2.0 A, 250 V, (T)) located on the inside of the instrument on the rear of the power inlet
connector.
High voltages are present within the instrument when operating and for some seconds
after switching off. Remove the mains lead before removing the cover for any reason.
The top cover is connected to the enclosure with a wire to ensure earth continuity. Do
not remove this wire, ensure it is intact before replacing the lid, taking care to avoid
pinching the wire between the lid and enclosure base.
Grounding
The instrument earth stud (right side when viewing the rear panel, and identified by the
symbol) must be connected directly to the vacuum system earth distribution point with
a low-impedance strap/cable (≥4mm2or ≤12 AWG). There must be no ferrite
components installed on it.

© Arun Microelectronics Ltd 2020. All rights reserved Page 10
Ion Gauge 1 & 2
Use AML-approved gauges with properly-screened leads. The ground braid of the Ion
Gauge cable must be connected to the instrument ground stud.
Ion Gauge leads should not be installed close to cables carrying high alternating
currents or through areas where there are significant alternating magnetic fields. They
should be constrained, since movement or vibration will generate charges or currents
and these may disturb UHV pressure readings.
Third-party Ion Gauge cables may not allow compliance with EU EMC Directives and
may lead to unstable emission. As a minimum, there must be an overall screen on the
lead and an inner screen on the collector connected to the BNC shell. These screens
must not connect either to the vacuum chamber or to each other. Interlock pins 1 & 3
must be connected together.
Pirani 1 & 2
AML Pirani Gauges PVU and PVB are suitable for use with this instrument. Pirani 1
pressure may be used for Ion Gauge Interlock and Autostart functions and should be
installed in the same chamber as the Ion Gauge if used for this purpose. Pirani 2 is normally used for backing-line pressure
measurement.
Process control relays
The terminal block cover (supplied) must be fitted to restrict access to the terminals if
they are used with voltages greater than 24 V. Take appropriate action to strain-relieve
the wiring.
Four single-pole, change-over relays are provided for process control and can be independently assigned to any gauge.
Contacts are rated at 5 A, 240 V maximum. The contacts of the relays are shown diagrammatically on the rear panel legend,
in the de-energised condition, adjacent to the terminal blocks to which they are connected.
Inductive loads, including contactor coils, should have “snubber”networks connected in parallel to avoid arc generation
which could interfere with the operation of this and other equipment. The external wiring is connected to the instrument
through a two-part pluggable terminal block. This can be removed and wired independently of the instrument. Ensure that
external wiring is of adequate cross-section for the load current. Strip and twist the wires (do not tin them) and poke into
the receptacle in the terminal block. Close the leaf on the wire by tightening the screw immediately above. Take
appropriate action to strain-relieve the wiring nearby and to restrict access to the terminals if harmful voltages are to be
present. Fit the terminal block cover supplied.
If the Bake function is to be used then Relay D must be assigned to Bake. It is used to switch on the Bake heaters when
energised. Do not connect heaters directly to Relay D; use a contactor and fit a snubber directly across its coil. The pressure
measurement during the bake cycle is read from Ion Gauge 1 only.
Bake Thermocouple
The K thermocouple tip must be isolated from the vacuum chamber and situated where it accurately represents the Bake
temperature. Mineral-insulated thermocouples with a miniature flat-pin thermocouple connector should be used.
Figure 1 Ion Gauge
Connector pinout
1
Interlock
2
Grid
3
Interlock
4
Filament Common
5
Filament 1
6
Filament 2