Safety controller for low-temperature cooling systems with two temperature sensor connections for a temperature range from +100°C to -196°C

SC 5 safety controller
The SC 5 safety controller consists of three functional components.

The first component is the temperature control. The temperature controller allows the user to set the desired setpoint temperature of the gas flow on the front panel or via the controller software. The controller then displays either the actual and setpoint temperatures separately or the two temperatures of the control and external temperature display sensor. In addition, the safety controller has an RS-485 interface that enables the user to address the controller via software and specify temperature ramps. In addition, the controller has an “auto-tuning” function with which the controller automatically searches for and reads in the necessary control parameters in order to achieve a high level of control stability. The controller has the option of using the internal temperature sensor to control the cold gas system and a second external temperature sensor to record and display the temperature of the sample to be tempered.

The second component is the safety monitoring of the heating elements. The two heating elements are monitored for the fixed safety limit temperature. If the internal temperature of one of the two heating elements (jet and heater) rises above the set safety limit temperature, the safety device switches off the cold gas system and sounds an alarm. The system can only be switched back on manually.

The third component is the LN2 vaporizer. The gas output is set using a rotary knob. This gas output can be selected manually between 0 and 100%. The amount of cold N2 gas produced depends on the capacity of the jet (LN2 vaporizer) and the set vaporizer capacity. The LN2 vaporizer (Jet) is available in power ratings from 100 to 1000 watts. If an LN2 vaporizer has an output of 1000 watts, this corresponds to a maximum N2 gas production of more than 14000 liters of cold gas per hour. (Jet- 100 watts evaporate approx. 2 liters of LN2 per hour, 1 liter of LN2 produces approx. 700 liters of N2 gas).