Teledyne 450H 4.0Maintenance, 4.1Replacing the gas filter element, Cleaning the Optical Cell

4.0Maintenance

4.1Replacing the gas filter element

The Model 450H comes equipped with a gas filter on the ozone inlet. These filters accept 25mm diameter glass fiber elements. Only filter elements of borosilicate glass or quartz fibers should be used. When the instrument is first installed, the sample filters should be checked at least once a week for particulate loading and replaced if necessary. Once the replacement frequency is determined, a regular schedule for filter replacement should be instituted.

For replacement 25mm filter elements, please contact Teledyne API’s sales department and request part number 02851.

Filter Replacement Procedure:

1.First ensure that the gas delivery line is not under pressure and has been purged of ozone.

2.Remove the four nuts securing the gas filter assembly.

3.Remove the bottom half of the filter housing

4.Examine the internal sealing o-ring and replace if necessary.

5.Pull out the stainless steel screen securing the filter element.

6.The element can now be removed and replaced. When re-assembling filter, make sure that the top stainless steel screen is pushed into the filter cavity, securing the element in place.

7.After re-assembly, the gas line should be pressurized with oxygen or dry air and checked for leaks using a bubble solution.

4.2Cleaning Exterior Surfaces of the M450H

If necessary, the exterior surfaces of M450H can be cleaned with a damp cloth. Do not attempt to clean any of the other surfaces of the instrument. Do not submerge any part of the instrument in water or cleaning solution.

4.3 Cleaning the Optical Cell

Over long periods of time the optical cell windows in the sensor assembly may become dirty and affect the operation of the instrument. Each time a zero calibration is done, the instrument can detect changes in the light transmission through the windows and will issue a warning when this value drops to an unacceptable level. The warning message “Optical Cell Warning” will be issued on the front panel and the “Cell Dirty” status output(See Section 1.6.3) will be turned on. The cell assembly should then be cleaned to avoid any degradation in measurement accuracy of the M450H.

P/N 02826B1 Teledyne API Model 450H O3 Monitor Instruction Manual - Page 39