8 Drying Agent
The tensiometer has a desiccant cartridge which dries the air used to make
the bubbles. This is only necessary when the temperature of the liquid to be
measured is considerably lower than the ambient temperature. Without the
desiccant cartridge, moisture would condense in the capillary. The drying
agent in the cartridge absorbs most of the moisture lowering the dew-point.
(The dew-point marks the beginning of condensation).
The desiccant cartridges come in lockable, air tight bags. When new, the
drying agent is blue. When the agent is saturated with moisture it turns pink.
The desiccant cartridge should be changed if half of the drying agent has
changed colour or if the measurements are getting unstable when measuring
in cold liquids. Additional desiccant cartridges can be supplied by the
manufacturer.