Sartorius YDK03MS Mode D'emploi page 16

Operation
Adhesion of the Liquid to the Wire
When immersing the sample holder (or sieve) in the buoyancy liquid, liquid travels
up the wire because of adhesion forces and generates a few additional milligrams of
weight .
Since the sample holder (or sieve) is in the buoyancy medium both when weighing
in air and when weighing in liquid, and the balance is tared at the beginning of each
measurement, the influence of the liquid meniscus can be ignored .
To reduce the surface tension and friction of the liquid on the wire, add three drops of
a surfactant (Mirasol Antistatic or a conventional detergent) to the distilled water in
the vessel .
Because of the buoyancy liquid travelling up the wire, the weight value may continue
to slowly change after the "g" has appeared . For this reason, the weight value should
be read as soon as the "g" appears .
Air Bubbles
The measurement errors which occur as a result of air bubbles sticking to the sample
can be evaluated as follows . If the air bubble has a diameter of 0 .5 mm, this will
produce an additional buoyancy of less than 0 .1 mg when weighing in water . If the air
bubble has a diameter of 1 mm, the additional buoyancy will be around 0 .5 mg, and if
the diameter is around 2 mm, roughly 4 .2 mg . It is therefore imperative that larger air
bubbles are taken off with a fine brush or similar .
Moisture can also be added in advance in a separate container .
16 Operating Instructions YDK03MS | YDK04MS