Glossary of Terms

Here you will find a glossary of specialised terms commonly used in thermostating and metrology.

S

Safety classes

It is possible to use non-flammable or flammable bath liquids with thermostats. The relevant safety-related requirements are given in DIN EN 61010-2-010. We correspondingly make a distinction between the NFL (non-flammable) classes with built-in overtemperature protection that is exclusively for non-flammable liquids (thermostats of the LAUDA Class A) and FL (flammable) with adjustable overtemperature protection and low level protection for flammable liquids (all other LAUDA thermostats).

Schulz-Blaschke (IV value according to Schulz-Blaschke)

Serves the purpose of the approximate calculation of the intrinsic viscosity of celluloses, polyolefines and others. K1 is an additional constant dependent on polymer.

Secondary side/Heat transfer medium side

Denominates the side of the temperature control unit from which the heat transfer medium is flown through. Heat transfer mediums (thermal oil, water) are chosen according to the operating temperature range and their respective application.

SelfCheck Assistant

This is a special feature of the LAUDA Proline. The SelfCheck Assistant checks all parameters before the actual start of operations and especially the switch-off methods of the heater control. The alarm or error messages are shown in clear text on the display. In addition, the system registers not only operating failures such as low level, but also points out the maintenance method such as cleaning of the cooling grid.

Setting resolution

The difference between two consecutive set values with digital set value setting. In the case of analogue set value adjustment with a digital display (C-S, K-S) it should be noted that it is possible to get a significantly higher resolution with a quasi-continuous set value encoder in addition to the setting resolution of the digital display under certain circumstances.

Slave controller

See external control.

SmartCool System

SmartCool System Offers greater cooling output, lower temperatures and the highest precision. LAUDA Proline cooling thermostats have a microprocessor-controlled cooling management - unique in this class. The intelligent cooling control increases or reduces cooling in perfect accordance with the required operating status. Furthermore, the automatic compressor control switches the compressor on - but only if it is really needed.

Solomon-Ciuta formula (Solomon-Ciuta)

Serves the purpose of the approximate calculation of the intrinsic viscosity of PMMA and others. No additional polymer characteristic data required.

Solvent

When changing from one bath liquid to another it is absolutely essential to clean the internal parts of the thermostat, the tube connections, as well as the external system. For this reason suitable solvents are listed for each bath liquid. In order to protect the environment it has however proved satisfactory in most cases to empty the thermostat completely and then to fill it with water with the addition of a surfactant, e.g. a commercially available detergent, and to heat it to approx. 80 °C followed by draining (not applicable with USH 400, Integra and WK). Ideally this operation should be repeated.

Sound pressure level

Sound pressure level is the measure for the sound radiation according to DIN EN ISO 11200. In contrast to the acoustic power level, the pressure level is always assigned to a defined distance. In practice both quantities are stated in dba.

Specific heat capacity

Specific heat capacity is the amount of thermal energy that is required for a temperature increase of 1 °C in a mass of 1 kg.

Specific viscosity (relative viscosity increase)

The relative viscosity minus one:

Standards

The safety stipulations for electrical laboratory equipment, and especially also those for thermostats, have been stipulated in the European standards EN 61010-1 and EN 61010-2-010, replacement for DIN 12879, among others. The terms and the stipulation of characteristic data is given in DIN 58966 Part 1 and Part 2 which are currently being revised and will shortly be replaced by DIN 12876-1 and DIN 12876-2.

Surface age

The age of a surface since its formation. In bubble pressure tensiometry, this is the period from the beginning of bubble formation to the hemispherical shape of the bubble. In drop volume tensiometry, this is the period between the formation and the separation of a drop.

Surface tension

The interfacial tension between a liquid and any gas.

Surfactant

An interfacially active substance. The reason for this activity is an asymmetric structure of the surfactant molecule, consisting of a hydrophobic (water-repelling) part and a hydrophilic (water-soluble) part. The interfacial tension is reduced by the adsorption of these molecules at the interface.

Suspension

A disperse system, i.e. a fine, but not molecular distribution of a solid body in a liquid.

System pressure

This is the pressure which is produced by pump pressure, vapour pressure at operating temperature and overlay pressure in the heat transfer medium system. Please pay special attention to the maximum system pressure because all components that are flown through by the heat transfer medium have to be suitable for the maximum system pressure (see pressure equipment directive).

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