SunTherm 100

Column Thermostat

The cooling effect due to the introduction of cold eluents on the column is eliminated as SunChrom provides an optional heat exchanger. This provides for narrower and more symmetrical peaks, even though it increases the system volume by a few µL.

The column oven SunTherm 100 provides the capability to maintain a precise temperature in the range from 5 °C to 100 °C. The heating transfer occurs via an aluminum block is in the heating area and provides for optimum contact with the column. The thermal energy is transmitted directly by contact to the metal. Since the SunTherm Column Oven does not include any movable parts it is exceptionally effective and reliable. 

Why do you have to thermostat the column?

An HPLC-separation is reproducible when the temperature of the column is maintained at a given temperature. In addition, some separations require an above or below ambient temperature. As examples, separations using a chiral phase frequently require cooling, while many ion exchange separations are optimized at elevated temperatures. In the same vein, the retention times of the compounds that are being separated and the selectivity are temperature dependent.

The influence of a change in the temperature on the separation can be eliminated with the use of a column oven that maintains a stable temperature. It should be noted that GLP requirements dictate the need for temperature control and documentation of the temperature. In addition, an elevated temperature of the separation column serves to lower column back pressure and leads to narrower peaks, which leads to the possibility of faster separations.


The entire length of the column is housed between aluminum blocks and with the pre-heating of the eluent the user obtains fast, optimal heating and fast transfer of heart to the column. The aluminum blocks are available as a number of lengths so that essentially all columns can be accommodated. The SunTherm Column Oven is available in two versions; the SunTherm 100 has a heater while the SunTherm 5 – 100 includes a heater and a Peltier-cooling system.

The microprocessor based controller provides control of two separate processes, heating and cooling. In the heating mode, the Peltier elements and the fan are disabled, while in the cooling mode, only the Peltier elements are in operation. The system continually monitors the temperature and both the heating and cooling elements are controlled so that the smallest change in temperature will activate the appropriate element to ensure that the desired temperature is maintained. Since there are no moving parts except for the fan, the SunTherm Column Oven is extremely reliable and rarely stops operating.