Teledyne 102E manual The UV Light Path, Pneumatic Operation, UV Lamp Shutter & PMT Offset, Rev A1

THEORY OF OPERATION	M102E/M501 TRS
	(Addendum to M101E Manual - P/N 04740 Rev A)

9.2. The UV Light Path

The following information is in addition to that contained in Section 10.2 of the M101E Manual - P/N 04740 Rev A.

9.2.1. UV Lamp Shutter & PMT Offset

Inherent in the operation of both the reference detector and the PMT are minor electronic offsets. The degree of offset differs from detector to detector and from PMT to PMT and can change over time as these components age.

To account for these offsets the M102E includes a shutter, located between the UV Lamp and the source filter, that periodically cuts off the UV light from the sample chamber. This happens every 30 minutes. The analyzer records the outputs of both the reference detector and the PMT during this dark period and factors them into the SO2 concentration calculation.

•The reference detector offset is stored as and viewable via the front panel as the test function DRK LMP.

•The PMT offset is stored as and viewable via the front panel as the test function DRK PMT

9.3. Pneumatic Operation

9.3.1. Sample gas Flow

See Figures 3-4. 4-1 and 4-2 for depictions of the internal pneumatic flow of both the M102E & the M501-TRS.

9.3.2. M501 SO2 Scrubber

In order to ensure that no ambient SO2 interferes with the analyzer’s TRS measurement the sample gas stream is passed through a chemical scrubber that removes SO2 from the sample stream before it is passed though the M501-TRS converter oven.

The SO2 scrubber is a Teflon encased, stand-alone unit containing a room-temperature catalyst tube mounted in the right side of the converter case (see Figure 3.2).

The SO2 scrubber material is consumed as it removes SO2. If the expected concentrations of SO2 are very high, the lifetime of the scrubber will be short. The expected life of the scrubber is approximately 1000 ppm-hours. See Section 8.1.1.3 for information on when and how to replace the SO2 scrubber material)

46 05514 Rev A1