Background of the invention Machine bases can deform to some extent during use in that during the manufacturing or handling process of the products the temperature in the base body-which must typically have a substantial mass in view of its stiffness and vibration resistance-is not the same throughout. Where a machine base is used as a base for modules fixed thereon for the manufacture and handling, respectively, of high-precision components or products, the extent of deformation of the machine base is a factor of significance for fabrication accuracy.

Summary of the invention The object of the invention is to improve production precision by providing means for temperature control of the base body. Temperature control in this context is understood to mean in particular the effectuation of as homogeneous a temperature as possible throughout the base body.

Preferably, -specifically there where the machine base forms part of a production line for high-accuracy components or substances that are fabricated in an environment of protective gas or air, -the base body comprises a channel system adapted for a gas, in this case the protective gas, to flow through.

If during the manufacture and/or handling of products, these products are surrounded by a protective gas such as contamination-free air, the channel system can be adapted for either the discharge of that protective gas or for the supply thereof. Both options have advantages and disadvantages.

The channel system is preferably provided with means for optimum exchange of the temperature of the base body and the gas flowing through.

Optimum temperature exchange can be effected, for instance, by providing the channel system with surface-enlarging ribs, cavities, etc.

By making use of the proposed features, the base body is held at the same temperature as homogeneously as possible. As a result, deformation, such as warp, etc. , of the machine base is prevented, so that the accuracy of the manufactured or handled products is improved.

No supplemental provisions need to be made when for improving the thermal management of the machine base, use is made of the air flow that is generated anyway for the purpose of the protection, for instance keeping dust-free of the environment of the products and the modules needed for manufacturing and/or handling those products, respectively.

As a result of the provision of the proposed channel system in the base body, moreover, material can be saved and the machine base can be lighter and cheaper. Obviously, this should not affect, for instance, the stability properties of the machine base.

In principle, the solution is applicable in all cases where there is a need for a stable and accurate base construction: - measuring systems; - precision production machines;

- optical testing tables; -test setups in a broad sense.

Especially when the invention is combined with a contamination-free ventilation system, there are major advantages because the air flow can then be combined with the air filter system by which the air is purified : - production of high-precision and dust-sensitive products, for instance in the semiconductor or microsystem technology; - uses in pharmaceutical handling systems, for instance for germ control.

Drawing Figure 1 shows an exemplary embodiment of the invention.

Description of the drawing Fig. 1 shows schematically a system 1 for manufacturing and/or handling high-precision products, for instance microelectronic components. The production system 1 comprises a casing 2, provided with an inspection and operating hatch 3. Within the casing 2, there is a machine base, for the most part formed by a base body 4. The base body 4 is supported by an underframe 5. Mounted on the base body 4 are a number of consecutive fabrication and measuring modules 6, jointly forming a production line. In the drawing, only one of the modules 6 is represented; the others are situated behind it or in front of it. The fixation and alignment of the modules 6 on the base body 4 requires great accuracy.

In practice, various modules dissipate heat during the production process.

As a result, the upper side of the base body 4 is warmer than the underside.

Moreover, not all modules 6 dissipate heat equally, so that the temperature distribution at the upper of the base body is not uniform either. For that reason, according to the invention, it is proposed to use means for

temperature control of the base body 4, which provide that the same temperature prevails throughout the base body 4.

In the drawing, it is represented by a number of arrows within the casing 2 that the production environment, that is, the environment of the modules 6, is surrounded by a protective gas, for instance contamination-free air, which is supplied within the casing by an air source 7. This air flow can be utilized for controlling the temperature of the base body 4, viz. by means of a channel system 8, arranged to allow a gas, in this case the contamination- free air, to flow through.

The channel system 8 comprises a collecting channel 9, the purpose of which is to provide that throughout the length of the production line the protective air is discharged (in the direction of the arrow) and is supplied to a "Contamination Control Unit"10, where the discharged air is purified, and is either recycled via a channel, not shown, to the air source 7, from where the air is supplied to the environment of the production line again, or discharged outside the casing 2.

The flow of the protective air can also be passed along the production line in the opposite direction, viz. from the channel system 8 upwards.

It is also possible to provide the machine base with, for instance, a double channel system, protective air being supplied through one part thereof and being discharged through another (separate) part thereof.

The channel system 8 can be provided with cooling ribs or cavities which enlarge the heat exchanging surface and thereby effect optimum exchange of the temperature of the base body and the air flowing through.