LaMotte SMART3, Руководство оператора

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SMART3 Colorimeter 09.16 13
a few minutes. The water percolates into the sample chamber displacing the air which
bubbles to the surface. When the bubbles cease to rise, the device has flushed itself
approximately five times and it may be raised to the surface for examination. The inner
chamber of the sampling device is lifted out and portions of the water sample are
carefully dispensed for subsequent chemical analysis.
A Snap-Plunger Water Sampler (LaMotte Code 1077) is another “in-depth” sampling
device which is designed to collect large samples which can be used for a multitude
of tests. Basically, this collection apparatus is a hollow cylinder with a spring loaded
plunger attached to each end. The device is cocked above the surface of the water
and lowered to the desired depth. A weighted messenger is sent down the calibrated
line to trip the closing mechanism and the plungers seal the sample from mixing with
intermediate layers as it is brought to the surface. A special drain outlet is provided to
draw off samples for chemical analysis.
Sampling of Closed System
To obtain representative samples from confined water systems, such as pipe
lines, tanks, vats, filters, water softeners, evaporators and condensers, different
considerations are required because of chemical changes which occur between the
inlet and outlet water. One must have a basic understanding of the type of chemical
changes which occur for the type of equipment used. Also, consideration should be
given to the rate of passage and retaining time for the process water.
Temperature changes play an important part in deciding exactly what test should be
performed. Process water should be allowed to come to room temperature, 20–25°C,
before conducting any tests.
When drawing off samples from an outlet pipe such as a tap, allow sample to run for
several minutes, rinsing the container several times before taking the final sample.
Avoid splashing and introduction of any contaminating material.
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FILTRATION
When testing natural waters that contain significant turbidity due to suspended solids
and algae, filtration is an option. Reagent systems, whether EPA, Standard Methods,
LaMotte or any others, will generally only determine dissolved constituents. Both EPA
and Standard Methods suggest filtration through a 0.45 micron filter membrane, to
remove turbidity, for the determination of dissolved constituents.** To test for total
constituents, organically bound and suspended or colloidal materials, a rigorous high
temperature acid digestion is necessary.
**LaMotte offers a filtering apparatus: syringe assembly (Code 1050) and membrane filters, 0.45 micron,
(Code 1103).