Glossary of Terms

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

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21 CFR-11

The guideline 21 CRF, part 11, issued by the American FDA authority, regulates the technical and organisational requirements which must be fulfilled in order to use electronic data and documents instead of paper in the development, authorisation and production processes.

Actuator

The actuator is an active component of the so-called control circuit. It is controlled through an adjusting command (see control variable) of the controller (see temperature controller) and triggers a measure that counteracts to the control deviation.

ACC range

ACC-range (Active cooling control area according to DIN 12876 standard) is the operating temperature range during operation with an active cooling unit. Example: working temperature range: -30 to 150 °C, ACC area: -30 to 100 °C. This information implies that the cooling unit cannot work continuously at temperatures of above 100 °C. The working temperature range is equal to the ACC-range in all LAUDA devices.

Adsorption

The accumulation of (amphiphilic) molecules at the surfaces and interfaces of liquids and solids. This leads, amongst other things, to a reduction in surface/interfacial tension.

Air-Blast Cooling Systems

Self-contained units, supplied with a liquid to air heat exchanger, circulating pump, fan and control gear. They are designed to remove heat from a process in which the coolant temperature can be above the ambient temperature (this is typically 10°C above the ambient i.e. 25°C ambient equals 35°C onto process).

Ambient temperature range

The permissible temperature range of the environment in which the unit functions perfectly. It is 5 to 35 °C for all LAUDA units given in this catalogue with the exception of the Integra and WK units. For the latter the upper limit is raised to 40 °C. This is especially important with respect to applications in industry.

ATEX

Directive 94/9/EC, also known as ATEX 100a, has been issued by the EC in order to harmonise fundamental safety and health requirements for devices, protection systems and components that are provided for use in accordance with the regulations for hazardous areas. This definition includes devices for safety, test and control that are required for use outside hazardous areas with regards to their explosion risks. Directive 94/9/EC is applicable to electric and non-electric devices, protection systems and components (electric and non-electric operating supplies).

Automatic cooling

A procedure used in cooling thermostats to save energy. The controller decides by means of suitable control logic whether the cooling unit can be switched off, as is the case in a warming-up process. As a result of the automated cooling an automatic sequence corresponding to the temperature control program has been made possible with cooling thermostats with built-in or external programmers.

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