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Life's twists and turns...on test

15/11/2005

We are currently testing lots of things.... balancing tests using models to simulate weights, motor movement tests and tests that will allow us to carry out more tests in the future...

The instruments will also have to be tested at each stage of construction. In order to do this we need a rotator to make the various parts gyrate, as they will do on the Gran Telescopio CANARIAS (GTC) to compensate for the earth's rotation.

THE TEST ROTATOR

The Instituto de Astrofísica de CANARIAS (IAC) is building two of the instruments for the GTC: OSIRIS (an Optical Imaging System for Integrated Low/Intermediate Resolution Spectrography) and EMIR (Infrared Multiobject Spectrograph). Both will be mounted at the Nasmyth focus, on platforms at either side of the elevation axis (these can be seen in the first video, “Parts of the GTC”).

A partial replica of the GTC's rotators, known as the "Nasmyth Rotator Simulator for Large Instruments", will be used to allow the different parts of these instruments to be tested throughout construction.

This simulator is in a special room at the IAC workshops known as the AIV room, which is used for assembling and testing large instruments.

Measuring two and a half metres in diameter at its anchor point and weighing 7,000 kg, the rotator is mounted on a bedplate* to isolate it from the floor of the room so that the tests cannot be affected by external vibrations.

The rotator can support instruments nearly 3 tonnes in weight which will be "hung" so that they rotate, imitating the observation process where field rotation caused by the rotation of the earth will be compensated for (you can find an explanation of what is field rotation, and how it is compensated for, in the second video)

Like the GTC's rotators, the test rotator was built by the Basque company TEKNIKER (Eibar-Guipúzcoa).

As you can see we are testing everything to get all the parts ready, including making them spin.

* bedplate:Mec. A heavy metal platform or frame to which an engine or machine is attached (Collins English Dictionary).

Natalia R. Zelman

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