The hydraulic principle of the tango and the big Unistats®

Conventional bath and circulation thermostats:

Conventional bath and circulation thermostats(Compatible Control Thermostats) work hydraulically with an open bath: in its simpliest version Case A (Pic 1) the object is temperature controlled within the bath itself, using internal temperature control, and is directly in touch with the temperature controlled heat transfer fluid. The bath fluid is not sealed from the atmosphere, but open and without pressure. In case B (Pic 1) the object is also temperature controlled directly in the bath and open to the atmosphere but using external  temperature control. Here, the bath level has to be controlled from both sides. Picture 2 shows the typical externally closed temperature control where the object is directly in contact with the heat transfer medium (D) or indirectly (C). In both cases the atmospherically open bath (A) in Picture 1 also serves as an expansion vessel for thermally induced volume changes.

The Unistat® principle

The new unsitat® system (Pic 3) optimally combines the possibilities of thermodynamics and intelligent microelectronics. A comprehensive alternative has been created compared to previous known temperature control methods, and is also being developed further. Todays Compatible Control Thermostats, successors of the classical digital thermostats, have received a clear improvement with the development of the Tango. The conventional method for the middle temperature range and for not too demanding requirements is still being used. In practical applications, all results clearly show that the Tango and the big Unistats® have established themselves for demanding users. There are several reasons for this. Instead of the integrated temperature bath, the Unistat® only has an expansion vessel for the case of C or D (Picture 2). Open baths are always operated as in B (Picture1). Here the expansion tank is easily isolated (Picture 3). The temperature control machine is hereby hydraulically sealed and can be placed under the table without a level problem. Externally closed systems (C or D, picture 2) will require the expansion vessel for thermally induced changes in volume. As no one has dictated that this expansion vessel must be temperature controlled, we do not, and for a good reason.

Result: The classical method of the Compatible Control Thermostats will continue to exist in the middle temperature range. This is alone dependent upon their special demands. When it comes to fast temperature changes and a wide temperature range the Unistat® principle is definitively the correct alternative. Without ballast, handicaps or compromises.