Novocool Cryosystem

The Novocool Cryosystem is an economical turn key temperature control system for applications in materials research. It can be used with all Novocontrol sample cells for dielectric and impedance spectroscopy.

The system sets or ramps the temperature of the sample under test. It is modular and can be combined with any Novocontrol BDS dielectric or impedance spectrometer.

The Novocool Cryosystem was designed for easy, safe and fully automatic operation enabling computer controlled experiments over several days without supervision as required for low frequency measurements.

Features

Economical temperature control system
Temperature range −100 °C ... +250 °C
Temperature ramps from 0.1 .. 20 °C/min
Temperature accuracy ±0.3 °C
Fast stabilization with nearly no overshooting by tuned control parameters
Low liquid nitrogen consumption (< 1.5 l/hr at T> −50 °C)
Microprocessor controller with 24 bit ADC and GPIB communication port

Dimensions (approximate):

Part	Width/cm	Height/cm	Depth/cm
Lab trolley	58	150	62
Dewar	65	155	65

Principle of operation

Novocool Dewar head — Novocool LN2 evaporator unit (top view)

Liquid nitrogen is transferred from a dewar into the Novocool cryostat by a flexible cryogenic transfer hose. The evaporation takes place in the Novocool cryostat by an electrical heating element, which accurately controls the temperature of the cold gas.

The gas flows directly to the sample cell which is inserted from the cryostat upper side.

The temperature is measured at the sample cell lower electrode. In order to optimize temperature control and establish save operation under any conditions, the temperature of the cold gas is measured with an additional gas temperature sensor. The Novocool cryostat is super isolated and therefore no vacuum is required.

The flow of liquid nitrogen is determined by the pressure inside the dewar. For optimized operation, the dewar pressure is adjusted by the Novocool microprocessor control unit. For this purpose, a second control loop is used consisting of a pressure sensor, dewar heater (to create pressure) and the pressure valve (to release pressure).