PVCi & PVCiDuo UHV Ion Gauge/Vacuum System Controllers
The PVC (Process/Vacuum Control) range of UHV gauge controllers represent a new concept in vacuum management, integrating precision UHV pressure monitoring with a range of on-board vacuum system management functions.
The PVC instruments run all commercial single and twin filament HV/UHV ion gauge heads, including the EpiMax range, VG, GP, AML, Varian etc.
PVC's integrate easily with vacuum system control via their 7 trips, 2 interlocks, and user-defined analogue output, providing user-defined control functionality such as pressure and interlock protection of the system, multi-step bake-out, auto pump-down/ion gauge start, timer function (e.g. TSP firing), and pressure sampling during degas for added system/gauge protection.
Additional functionality is provided via 2 "slots" accommodating optional modules. Installation of Pirani modules provides for backing pressure monitoring (atmosphere to <10-3mB) and auto-pump down/ion gauge power up. As well as EpiMax EMP16 and EMP8 Pirani gauge heads, Thyracont VSP521/522 and VG Pirani gauges are supported. The type K thermocouple module facilitates multiple ramp/soak UHV system bake-out, enabling integrated pressure, time and interlocking with minimal external wiring.
Manual operation is via an easy to use touch panel menu system; for automated installations, all aspects of the PVCs can be controlled using an efficient MODBUS protocol via the multi-drop RS232 and RS485 interfaces (fitted as standard).
The functional differences between PVCi and PVCiDuo are:
| | PVCi | PVCiDuo |
| Number of ion gauge heads, independent/simultaneous operation and degas | 1 | 2 |
| Filament types | W & Ir | Ir |
| Degas Powers | 1,2,3,6,
12,20,30W | 1,2,3,6,
15,30W |
| Pump Down function | Y | N |
| Timer function | Y | N |
As indicated above, the PVC controllers have slots for 2 optional "modules". Modules can be supplied pre-installed, or can be fitted by the end user.
There are 3 modules available at present:
- "T" module for EpiMax EMP16 & EMP8 Pirani gauge heads - see EM Pirani gauges and Thyracont VSP521/522 Pirani gauge heads
- "V" module for VG Pirani gauge heads
- "K" module for Type K thermocouple monitoring. Provides for bake-out support
General
| Dimensions | 1U high 19" rack mounting.
Depth 257mm excluding connectors
Weight: PVCi: 6.8kg; PVCiDuo: 7.3kg |
| Power | 230/115Vac (+10-15%).
Typical 10VA + dissipated ion gauge power |
| Display | 20 character green/blue VFD alpha-numeric
4 brightness levels.
0, 1 or 2 decimal place resolution |
| Environmental | Internal fan-assisted temperature controlled
Operating environment 0-40°C |
| Units | User-defined: mBar, Torr, Pascal |
Ion Gauge
| Type supported | Single/dual filament HV and UHV Ion/Bayard Alpert gauges. 10-13 to 10-2mBar |
| Gauge Connector | Filaments & Grid: 6-pin "Qikmate"
Collector: Insulated BNC |
| Sensitivity | 0.1 to 99.9 mB-1 |
Potentials
Normal/Degas | Grid: +190V/+650V
Filament: +40V/0V |
| Filament drive | Tungsten (PVCi only): 14V @ 5.5A
Iridium: 7V @ 3.2A |
| Emission | Fixed: 0.1, 0.2, 0.5, 1, 2, 5 & 10mA
Auto-ranging: Pressure dependent with 1 decade hysteresis
User-defined min/max emission current |
| Degas | Soft-start ramped to user-specified value. Rise and hold ramp times 1 to 999 mins
PVCi: 1,2,3,6,12,20 & 30W
PVCiDuo: 1,2,3,6,15 & 30W |
| Quick Degas | 1 minute at user-specified power |
| Digital | A/D 12 bit: 4/8 times oversampled 10/second.
Low pass digital filter 0.1-9.9 seconds.
RIPPA (Rapid Increment Pressure Protection Algorithm) ensure rapid response during pressure bursts. |
| Protection | Thermal trip
Connector interlock
Filament overcurrent: 3A for Ir, 6A for W
Over/under emission
Over pressure |
| Electrometer | Thermally stabilized logarithmic amplifier
Pressure range <10-12 to 10-2mB at sensitivity of 10mB-1 (gauge dependent). |
| Gauge lifetime | Gauge lifetime monitor |
| Spec | 4 change-over relay: 1A @ 24Vdc/0.5A @ 125Vac. Max switched power 30W/62.5VA
3 open collector: NPN darlington 250mA @ 20V
[Higher currents with the PVCiRL7 unit] |
| Connector | DB25 male (shared with digital inputs) |
| Assignment | None, ion gauge(s), Slot A, Slot B, pump-down, bake-out, timer, comms... |
| Direction | > or < trip level |
| Trip level | 10-13 to 10+6 absolute
Normal (on/off action), override or inhibit |
| Hysteresis | User-defined from 1x (none) to 99.9x |
| Spec | 2 off
Opto-isolated. 3-32Vdc driven (2k2Ω). |
| Assignment | Inhibit of ion gauge(s), pump-down, bake-out, timer...
Remote control of ion gauge/degas... |
| Operation | Normal (on/off action), override or inhibit |
| Module Types | "E": Suitable for EMP16 & EMP8 Pirani gauge heads and Thyracont VSP521/522 Pirani gauge heads. Constant filament temperature
"V": Suitable for VG Pirani gauge heads |
| Range | Atmosphere to 10-03mB |
| Capabilities | User assignable to trips
User assignable interlocking
Auto pump-down
Auto start of ion gauge etc. |
| Module | Type "K" module for type K thermocouple with cold junction compensation
Operating range: 40-400°C (±2°C < 250°C; ±3% > 250°C) |
User-defined
Assignments | Control to heaters via assigned trips.
Interlock from user-defined pressure reading, interlock inputs; options: suspend, fail... |
| Bake-out | Up to 6 ramp/soak steps each up to 99.9hours
User-defined hysteresis (1-99°C) |
| Spec | 12-bit resolution @ 5 times/second |
| Assignment | Ion gauge, Pirani, ion gauge+Pirani...
Auto-corrected for sensitivity and emission current |
| User options | Log or linear
Voltage range output
Pressure range output |
| Connector | Standard 3.5mm jack socket |
| Spec | On/off timer allowing on/off periods of 6 seconds to 1 day each |
| Application | Pump regeneration, TSP firing |
| Dependencies | Ion gauge pressure, interlocks... |
| Interface | Multi-drop RS232 & RS485 |
| Connectors | RJ45 |
| Protocol | MODBUS. Complete instrument control.
Floating point resolution data transfer. |
Rear panel view of PVCiDuo controller
Summary:
- 1U 19" rack unit
- Single(PVCi) or dual (PVCiDuo) twin filament, UHV/HV ion gauge head
- 10-13mB to atmosphere
- Thoria- or Yttria- Iridium and Tungsten filaments
- 7 emission ranges or Auto-ranging emission
- Ramped power degas
- Pressure measurement during degas
- RIPPA - rapid response to pressure bursts
- Precision, stable electrometer
- Gauge head lifetime
- 7 output trips
- 2 input interlocks
- User-defined analogue output
- Integrated, interlocked, multi-step bake-out controller
- Pirani support
- Auto pump-down
- Timer function
- Simple to use manual interface
- Full control over MODBUS interface over multi-drop RS232/RS485
Applications:
- All HV and UHV system pressure and interlock monitoring, and process control
- UHV system bake-out management
- Automated UHV system management
- MBE flux monitoring