Operating Principle - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

UltiMate 3000 Series:
NCS-3500RS and NCP-3200RS

8.3.2 Operating Principle

The fundamental requirement for a column compartment is the ability to maintain the
preset temperature as precisely as possible. Temperature stability plays an important role
for temperature equalization. The NCS contains advanced electronic circuitry that
maintains the temperature with a precision of ±0.1 °C.
The thermo-optimized design of the column compartment reduces the time required to
equilibrate the temperature between the column and the solvent.
Thermoelectric elements heat the column chamber and all internal components to the
preferred temperature (settable in 0.1 °C increments). Using a heat exchanger, they allow fast
temperature changes and ensure independence from the ambient temperature.
All this ensures that
• The temperature of the stationary phase remains constant over the total column length.
• The column and the solvent have the same temperature during the analysis.
Under these conditions, the analytical separation is performed at the nominal temperature.
This minimizes fronting and tailing of peaks, as well as retention time variations.
The column compartment has no active cooling system and thus, the temperature in the
compartment cannot be reduced below a temperature resulting from the ambient temperature
and self-heating of the module. Therefore, the temperature set point must be at least 7 °C
higher than the ambient temperature.
Page 230 Operating Instructions