Panning Vacuum Sensor Maintenance Guide

Magnetic demagnetization (extremely rare): Check the magnetic field strength using a Gaussian meter. If it is below 0.05 T, replace the sensor

6.2 High or non-linear readings (compared to reference gauge)

Possible cause inspection and resolution

Cathodic pollution leads to abnormal secondary electron emission. Cleaning or replacing the cathode is necessary

Particles or burrs inside the sensor causing partial discharge. Disassemble and inspect, and blow with compressed air

Leakage current is large (insulation contamination). Clean ceramic insulation and dry it

Controller calibration offset can be adjusted using Leybold calibration service or comparison standard gauge

6.3 Unstable and jumping readings

Possible cause inspection and resolution

Intermittent plasma or sputtering in the process, adding baffles or adjusting installation positions

Poor cable shielding, use double shielded cable due to electromagnetic interference, check grounding

Vacuum pressure fluctuation inspection system for air leakage or pump performance

Internal looseness of sensor, reassembly and tightening

6.4 Difficulty in ignition (failure to ignite even at a pressure of 10 ⁻ mbar)

Possible cause inspection and resolution

Oxidation or contamination of cathode surface, polishing of cathode plate or replacement

Insufficient High Voltage Output (<1.5 kV) Check Controller Settings

Magnetic field weakening inspection: Check if the permanent magnet has demagnetized due to high temperature (if baked above 200 ° C)

Replace the anode ring or cathode plate if the electrode gap is too large or deformed

6.5 Leakage or flange leakage

Possible cause inspection and resolution

O-ring (KF flange) aging replacement centering ring O-ring

CF flange metal seal ring damaged, replace oxygen free copper gasket

Check the O-ring or metal sealing surface for poor sealing of the sensor housing and tighten it again

Precautions for replacing old or faulty sensors

When you need to replace a discontinued or irreparable cold cathode vacuum timer, PR sensors are an excellent alternative. Please verify the following points:

7.1 Flange compatibility

The old standard flanges are usually DN 25 KF, DN 40 KF, or DN 40 CF. The PR series offers the same specifications and can be directly replaced.

If the flange sizes are different, variable diameter flanges (such as DN 25 to DN 40) can be used.

7.2 Electrical Interface

The old regulations may use 4-pin or 6-pin circular connectors, while PR sensors typically use high-voltage coaxial cables (SHV or MHV) or BNC. The output interface of the controller needs to be checked, and if necessary, an adapter cable should be made.

The measurement principle is the same (Penning discharge), and most brands of Penning gauge controllers can drive PR sensors, but the high voltage polarity (usually anode positive, cathode grounded) and sensitivity (current pressure curve) need to be checked. The curve of the Leybold controller is pre-set, and third-party controllers may require manual calibration.

7.3 Baking Requirements

If the system needs to be baked above 200 ° C, the CF flange version must be selected and the cables and controller must be removed. The PR sensor (without electronic components) can be baked to 400 ° C.

7.4 Measurement Range

The measurement range of the old regulations may be different from that of PR. The minimum measurement limit for PR series is usually 10 ⁻⁸ mbar (PR 81). If the system needs to measure 10 ⁻⁹ mbar, a higher sensitivity model (such as Leybold PENNINGVAC PTR series or hot cathode gauge) should be selected.

7.5 Cables and Controllers

The PR sensor itself does not include a controller. If you only have sensors without a matching controller, you will need to purchase an additional controller (such as Leybold GRAPHIX series or Center series). Third party Penning gauge controllers can also be used, but it needs to be confirmed that their output high voltage and current measurement ranges are compatible.

Suggestions for Accessories and Spare Parts

To ensure the long-term reliable operation of PR sensors, it is recommended to stock the following spare parts:

Recommended inventory for spare parts usage

Replace 2-3 worn or heavily contaminated cathodes with titanium cathode plates

5 O-ring seals (KF flange) for centering ring

Two oxygen free copper gaskets (CF flanges) are used for sealing

1 spare coaxial cable (with connector)

Baffle reduces pollution by 1 (recommended to be used immediately upon initial installation)