Variable temperature cryostats with the sample located in a column of static exchange gas. These systems offer excellent temperature stability and are used with LHe and LN2 as needed.
The Janis Research VariTemp (VT-200) system is an exchange gas insert for use with Janis CNDT series Dewars. The VT-200 offers an operational range of 4.2 to 77 K (LHe) and 77 to 300 K (LN2) with enhanced temperature stability
for use in optical and non-optical experiments.
The VT-200 utilizes an exchange gas column to form an adjustable thermal link between the sample and the liquid cryogen. The output from a bifilarly wound heater on the sample mount is monitored and controlled by an automatic temperature controller to
provide accurate sample temperature. Samples are located in the exchange gas column.