Module And Sensor Replacement - Instrutech CVM211 User Manual

Instruction Manual CVM211 Stinger
o
drying, or the gauge may be gently heated provided temperature doesn't exceed the specified limit of 40 C,
operating.
Coatings: Some gases can condense on sensor surfaces, forming a solid coating, which changes the rate at
which heat is removed from the sensor. Some of these coatings may be removed by cleaning the gauge.
Particles: Particles generated by the process may enter the gauge during the process cycle or during the venting
cycle. The result is interference with heat removal from the sensor. In this case cleaning may be able to remove
particles from the gauge. However, particulate contamination is the most difficult to remove as particles can
become stubbornly trapped inside the gauge. In some processes, solid particles are created during the process
throughout the chamber including inside the gauge. Particles tend to form on cooler surfaces such as in a gauge
at room temperature. You may slow down the build-up of particles in the gauge by keeping the gauge warm
(within specified limits) during the process cycle.
Particles in the process chamber may be swept into the gauge during the vent cycle. The CVM211 has a screen
built into the gauge port to help keep the largest particles out of the gauge. In very dirty applications, or where
particles are small enough to get through the screen, an additional filter installed on the inlet may help prolong
the gauge life.
In some vacuum processes, desorbed and sputtered materials from the process may enter vacuum components
connected to the process vacuum chamber by line-of-sight transport especially under high vacuum conditions,
i.e., in the molecular flow regime. To prevent materials that may be transported via line-of-sight momentum
from entering your vacuum gauge or other components, it is advisable to install some form of apparatus that
o
will block the line-of-sight. In many cases a simple 90 elbow may help prevent or reduce the transport of
particles from entering your vacuum gauge.
In the event of gauge contamination please contact the factory to return the gauge for possible cleaning if the
gauge has not been exposed to hazardous materials.
8.5

Module and sensor replacement

The CVM211 module is factory calibrated for the specific sensor (gauge tube) installed in it. If the device fails for
any reason, return the CVM211 to the factory to determine if either the sensor or the electronics could be
replaced or if the entire module should be replaced.
InstruTech
Page 25