horiba OCMA-500, Инструкция по эксплуатации

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Measurement
48
Examples of measurement by extraction outside the product
This section describes examples of extraction performed outside the product without using the
built-in extractor.
The methods described below are only examples for reference. These methods may not be
the optimum methods for some sample types. Use an extraction and measurement method
that is appropriate for the actual sample.

Oil content in water
For the following types of sample water, extraction must be performed outside the product
prior to dispensing the sample into the product.

Sample water that has an oil membrane or oil drops floating on the surface
It cannot be measured in a measuring utensil. Extraction must be performed using the
entire sample.

Sample water containing large amounts of suspended material (sand, organic materials,
etc.)
It will clog the measuring utensil or internal filter, and may damage the measuring utensil
or the product.

Sample water that is difficult to separate from the solvent after extraction (sample water
containing emulsifying substances)
If any incompletely separated solvent is sent to the water filter, emulsifying substances or
water content in the solvent may cause clogging in the water filter and an accurate
measurement will not be possible.
Note
The water filter in the product serves to remove water particles. However if the sample water contains
emulsifying substances, fine water particles may pass through the water filter. When this type of
sample is measured repeatedly, the water filter tends to clog and accurate measurement is no longer
possible.
If the measured value suddenly becomes a negative value or extremely low value, it is likely that water
has entered the measurement cell due to water filter clogging or damage. (A negative value indicated
during zero calibration is not abnormal.)
Replace the water filter at regular intervals, even if it does not appear to be dirty (refer to "Replacing
the water filter" (page 99)).

Checking layer separation
If a sample potentially contains emulsifying substances, check if the solvent layer and water
layer are separated in advance.
Tip
The following are typical examples of water that is likely to contain emulsifying substances.

Miscellaneous domestic gray water

Industrial wastewater

Activated sludge water (when the killed bacteria in the activated sludge is introduced, the content
of the bacteria dissolves and acts in the same way as emulsifying substances.)

Items required

Glass container with a lid (screw-top bottle is recommended) (50 mL)

Sample water

Clean solvent S-316 (optional)