18 PET Plus User Manual
3.6 CONNECTING THE PROBE
The probe is connected to the socket on the top
rear of the vertical column.
Store the probe in the probe holder at the right
hand side of the vertical column. Ensure that the
body of the probe rests onto the probe holder so
that the large knurled nut is below the holder.
Shown: Probe connection
3.7 VACUUM PUMP
The recommended pump is a BOC Edwards RV rotary vane pump, which is a two-stage, oil-sealed,
sliding-vane vacuum pump. The pump has a NW25 inlet port (item 4) and a NW25 outlet port (item
7), a gas ballast control (item 5) and a mode selector (item 11). When the pump is switched off, an
inlet-valve seals the inlet and prevents the suck-back of air and oil into the vacuum system.
An internal oil pump delivers pressurised oil to the vacuum pumping mechanism in the RV pump.
The level and condition of the oil can be viewed through a sight glass (item 8). Two oil filler-plugs
(item 6) and an oil drain-plug (item 9) are provided on the oil-box.
The motor is fitted with an on/off switch (item 12) and an internal thermal overload device. When the
motor is too hot, the thermal overload device switches off the pump. The thermal overload device has
an automatic reset and when the motor cools down, the device resets.