Vacuum-Resistant Oxygen Probe for PVD or Magnetron Sputtering
Main part of the ZIROX vacuum probe is a potentiometric zirconia solid electrolyte cell.
Due to various oxygen partial pressures (inside and outside the vacuum recipient) a voltage occurs between measuring and reference electrode. This voltage is proportional to the logarithm
of the oxygen partial pressures. From the cell voltage the oxygen partial pressure at measuring electrode can be calculated according to the NERNST equation.
The connection head contains the electronics for heater control and signal processing and the membrane pump for the reference gas supply.
The ZIROX vacuum probe serves for the determination of oxygen partial pressures in low pressure equipment. Typical examples are measurements in vacuum processes (PVD, magnetron sputtering or other plasma processes), in surface treatment applications as well for measurements for material-scientific investigations.
In contrast to the ZIROX normal pressure probes the vacuum probe is not calibration-free. The reasons are the special sensor heater (inside the probe tube) and several conditions at the measuring electrode (energy removal depends on gas pressure and thermal conductivity). Therefore, isothermal electrodes, required for the correct using of the NERNST equation, cannot be realized. For process control, however, the use of empirically determined values is sufficient in most cases. For the measurement of oxygen partial pressures, the user must calibrate the probe (test measurements).
Technical Data Vacuum Probe
|Inbuilt length||140...300 mm|
|Diameter||6 mm, with protection tube 16 mm|
|Dimension clamp head||150 x 63 x 35 mm|
|Flange||KF40, others on request|
|Max. temperature at flange||60 °C|
|Power supply||24 V DC +/- 10 %|
|Current consumption||1,2 A|
|Heating power||30 W|
|Pressure range||1,5 x 105...1 x 10-5 Pa|
|Sensor voltage range||0...400 mV oder 0...1200 mV|
(range changing on curcuit board)
(oxygen partial pressure)
|1 x 105...1 x 10-21 Pa|
|Output signal||0-20 mA|
|Accuracy||< 5 % rel. error|
|Sensor working temperature||700 °C (electronically controlled)|
|Offset (with protection sleeve)||-15...-20 mV|
|Helium leak rate||< 10-8 mbar l/s|
|Gas flow||max. 10 m/s|
|Reference gas||surrounding air|
|Reference gas flow||5...10 l/h (by internal pump)|
(Typ 423 6pol., Fa. Binder, Best.-Nr.: 99-5622-15-06):
|1||+ 24 V|
|3||+ Iout||20 mA corresponds to 400 or |
1200 mV (as adjusted)
|5||Ready contact |
|60V/1A DC or|