Manual

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O:\_VST PAPERWORK\SENSOR PAPERWORK\SENSOR BOOKLETS\WDS\150101.DOC November 27, 2006

insert the trigger pin through both metal tubes. You can now release the balls. Pull the trigger pin

out slightly until it extends 1 cm beyond the

side of the metal tube.

A sharp tug on the retrieving line is all

that is required to trigger and seal the water

sampler. If you try triggering the sampler out

of the water, be sure that no one is standing

near by because the closing action is very

quick and the trigger mechanism will swing

wildly. The sampler is designed to properly

trigger under water.

To obtain a sample from a desired

depth, mark the retrieving line by wrapping

tape around the cord at the desired distance

from the sampler body. Arm the sampler, and

slowly lower it over the side of the boat or

dock until the mark you've made is touching the water. If the sampler tends to float instead of

sink, drop the sampler from a small height into the water. The white balls must flood if the

sampler is to sink. To capture the sample, take a firm grip on the line then pull sharply upward.

A quick tug of only a few inches is preferable. Slowly pull the sampler back out of the water.

To use your water sample, hold the water sampler vertically and gently pull the top ball up

and to the side. Be careful not to agitate the water because this will introduce additional oxygen

into the sample and affect any measurements of dissolved oxygen that you may make. The sample

may be withdrawn by opening the pinch cock.

When the sampling is completed, rinse your equipment with fresh water then dry.

Caution: Do Not Store the Water Sampler in the Armed Position.

Applications:

Dissolved Oxygen and Biological Oxygen Demand (BOD):

Oxygen can get into the water by a variety of methods; diffusion through the water's

surface, aeration by waves breaking or rapids splashing over rocks or water falls, and

photosynthesis from aquatic plants. Three fourths of the earths oxygen is produced by oceanic

algae. Animals living in the water require oxygen to live. If there are too many microscopic

animals in the water then the oxygen supply will be depleted. For example, if the water contains a

large amount of biodegradable material, bacteria will try to reduce this material into simpler

forms. This process uses up large quantities of oxygen. The Biological Oxygen Demand (BOD) is

a measure of the amount of oxygen used by living organisms in the water. Testing for BOD shows

the long term effects of biodegradable wastes in a given area whereas oxygen content tests report

on the conditions at the moment the test was made.

Procedure: