Part III | Model 6600 | |
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5.5.4Oscilloscope Display of the I to E Converter Output.
The output of the I to E Converter is observed at the output of the second amplifier. The objective of this operation is to set up the optical system and the gain of the second amplifier in such a way that the analyzer keeps operating within its dynamic range, despite variations in turbidity and changes in background component levels. It is therefore important to mea- sure these components in the sample water.
The “reference” medium against which this data is obtained is either deionized or distilled water, city tapwater, or pure ocean water in the sample cell. While the transmittance of the cell filled with different references may differ, for this purpose these are negligible. Choose the reference that is most abundantly available on the site, usually tap or ocean water, and use it as the reference water.
Connect an oscilloscope to TP2. The oscilloscope displays the measur- ing and reference pulses in an alternating pattern. The display is created by the light passing through the reference and measuring filters as they are brought in and out of the light beam by the rotating filter wheel. These light pulses are converted to electronic energy which is amplified and brought to TP2. The base line represents the blocking of the light beam by the opaque part of the filter wheel.
To identify which of the pulses is the measuring peak, insert a piece of flat glass or clear plastic in the light beam. The peak that becomes the shortest (retracts excessively) is the measuring filter pulse.
5.5.5Background Signal Level Determination
1.Draw representative Zero fluid a sample from the grab sample port using valve V3 of the sample system into a clean(Hydrocarbon free) one gallon bottle.
2.Collect the sample through filters F1 and F2. This removes non- dissolved oils and solid particulates (turbidity). The filtered sample through both F1 and F2 removes both
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