Advanced Instruments 3320, Руководство пользователя

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of the solution. Managing the plateau temperature for precise measure-
ment is the basis for several patents issued to Augustus Fiske.
The time over which liquid/solid equilibrium develops and is main-
tained, is a function of the speed with which the heat-of-fusion is liber-
ated vs. the speed it is transferred away, or absorbed, by the surrounding
environment. This ratio can be slowed and the equilibrium time
stretched, to give a distinct plateau height measurable to 0.001°C.
Sensitive thermistor probes monitor the sample temperature and control
the thermoelectric cooling element. Microprocessor control and auto-
mated operation minimize imprecision due to operator technique.
The following Standard Freezing Curve illustrates the temperature of a
sample as it progresses through the freezing cycle and shows the action
of the instrument at each stage of the cycle.
Definitions
Solution : A homogeneous mixture of solute and solvent in which the
solvent is usually the major component, and the solute is the minor
component.
Concentration : The ratio of solute to a given amount of solvent
(molal), or ratio of solute to solution (molar).
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Advanced ® Micro-Osmometer Model 3320 User’s Guide
Standard Freezing Curve