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Thermo Scientific Orion AQUAfast AQ3010 Turbidity Meter User Guide
Air or other trapped gases should be removed before measurement .
Degassing is recommended even if no bubbles are visible . There are three
methods commonly used for degassing:
• Addition of a surfactant: This involves adding a surfactant to the
water samples to lower the surface tension of the water, thereby
releasing trapped gasses .
• Application of a partial vacuum: A partial vacuum can be created by
using simple syringe or vacuum pump . This is only recommended
for ultra-low turbidity measurements .
• Use of an ultrasonic bath: This may be effective in severe conditions
or in viscous samples, but not recommended for ultra-low
measurements .
Each of the method above has its own advantages and disadvantages . For
instance, under certain sample conditions, the use of vacuum pump or
ultrasonic bath may actually increase the presence of gas bubbles .
Samples should be measured immediately to prevent changes in particle
characteristics due to temperature and settling . Temperature can
affect particles by changing their behavior or creating new particles if
precipitates are formed . Dilution water may dissolve particles or change
their characteristics . It is recommended to take samples only when the
turbidity meter is ready to be operated . Samples should not be drawn
and allowed to sit while the instrument warms up or is being readied .
Degassing
Timeliness
of Sample
Measurement