Model OUM980 with OUSAF21 Inline Sensor
Maintenance
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6.4
Sensor Window and Gasket Replacement
Sensor optical pathlength is established by the window type(s) used. Each analyzer-sensor pair is configured for a given pathlength.
Windows must be replaced with the same type to maintain pathlength. The illustration below is a typical flowcell assembly. Figure
the available window types and possible pathlengths for sensors up to 2" line sizes.
Replacement of windows or window seals, changing window spacing or other maintenance requiring the disassembly of the sensor
uses the following procedure:
Note:
To replace and/or change the windows and seals, the sensor must be removed from the process line.
Figure 6.3: Typical Flowcell/Window Replacement
1.
Remove the lamp and the detector housings from the sensor body.
2.
Remove the 4 socket head screws from each window retaining ring and remove the rings. Be careful to loosen the screws
evenly and alternately around the window retaining ring. If the window is ‘stuck’, apply Acetone to the window seal area and
let soak for several minutes. This may assist in freeing the windows from the seals.
3.
Gently push/ease the windows out of the sensor.
4.
Inspect the window area and clean as necessary. Inspect the windows for any signs of abrasive wear or chipping. If any is
apparent, replace the windows. Discard the 'O' rings and replace with new ones of the same material type. Re-assemble the
sensor in the reverse order, taking care to cross-tighten the window retaining ring screws evenly to prevent uneven seating. If
the sensor pathlength has been changed, the analyzer module must be configured to reflect the new pathlength. After every re-
assembly of an OUSAF21 sensor, it is necessary to carry out a liquid or Easycal™ calibration with its associated analyzer.
Note!
Upon re-assembly, insure that the lamp assembly is mounted on to the side of the flow cell with the “shorter” length of the two
windows.
5.
Remove the lamp and the detector housings from the sensor body.
6.
Remove the 4 socket head screws from each window retaining ring and remove the rings. Be careful to loosen the screws
evenly and alternately around the window retaining ring. If the window is ‘stuck’, apply Acetone to the window seal area and
let soak for several minutes. This may assist in freeing the windows from the seals.
7.
Gently push/ease the windows out of the sensor.
8.
Inspect the window area and clean as necessary. Inspect the windows for any signs of abrasive wear or chipping. If any is
apparent, replace the windows. Discard the 'O' rings and replace with new ones of the same material type. Re-assemble the
sensor in the reverse order, taking care to cross-tighten the window retaining ring screws evenly to prevent uneven seating. If
the sensor pathlength has been changed, the analyzer module must be configured to reflect the new pathlength. After every re-
assembly of an OUSAF21 sensor, it is necessary to carry out a liquid or
Easycal
TM
calibration with its associated analyzer.
Note!
Some window faces may not be parallel to each other. This is normal, especially with fire-polished quartz windows. Take care to
ensure pathlength gauge does not scratch window faces.
