2x8.4m TELESCOPE
TECHNICAL SPECIFICATION
VERIFICATION PLAN AND ACCEPTANCE TESTS
August 25th, 1997
Approved and prepared by: Gianpietro Marchiori/EIE
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LBT PROJECT 2x8.4m TELESCOPE |
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TECHNICAL SPECIFICATION VERIFICATION PLAN AND ACCEPTANCE TESTS | ||
August 25th, 1997 Approved and prepared by: Gianpietro Marchiori/EIE | ||
INDEX
1.0 INTRODUCTION
1.1 Dimensional Checks
1.1.1 Overall dimensions of the telescope structure
1.2 Alignment Checks
1.3 Mass Checks
1.4 Functional Tests
1.4.1 Structure tests
1.4.1.1 Static testing of the telescope structure
1.4.1.2 Dynamic testing of the telescope structure (only assistance)
1.4.1.3 Balancing test of telescope
1.4.1.4 Jacking system tests
1.4.2 Test of hydrostatic bearing system (only assistance)
1.4.3 Test of the telescope drives (only assistance)
1.4.4 Test of the encoders (only on site)
1.4.5 Test of the cable wrap systems (only on site)
1.4.5.1 Test of the elevation cable drape
1.4.5.2 Test of the instrument cable wraps
1.4.6 Test of the brakes (only assistance)
1.4.7 Test of the auxiliary drives (with assistance of the drives' supplier)
1.4.8 Test of the stow pins (with assistance of locking supplier)
1.4.9 Test of auxiliary equipment
1.4.10 Test of M1 covering systems (with assistance of the M1 covering supplier)
1.4.11 Tests of spiders
1.4.12 Tests of Safety Equipment
2.0 ACCEPTANCE TEST REVIEW
ANNEX
The present document describes the main verifications to be performed on the telescope structure pre-erected both in factory (preliminary acceptance test) and on site, Mount Graham (final acceptance).
The preliminary acceptance test shall include:
as specified in detail hereafter. The tests shall be done in the above given sequence.
The final acceptance tests, including mass dummies for the M1 mirrors, shall be performed after site erection and shall include:
as specified hereafter.
The contractor is responsible for the definition and preparation of the procedures for each test of the preliminary acceptance. These procedures are subject to P.O. approval prior to start preliminary acceptance checks.
For the preliminary acceptance of the telescope structure the contractor shall perform the measurements which are specified hereafter.
Check of the following overall dimensions of the telescope structure, according to the telescope drawings.
Height: measured for azimuth ring level to the top supporting arms
Width: measured along the altitude axis from elevation platform end to end
Width: measured perpendicular to the altitude axis at the maximum extension
Diameter of the azimuth ring and of the azimuth floor
The measurement accuracy shall be better than ±1mm.
The contractor is responsible for the alignment of the telescope axes including the alignment of related subsystems like the hydrostatic bearing system and drive system.
The following verifications shall be carried out during the assembly activities and before the alignment checks, in compliance with the reference drawings:
For the preliminary acceptance of the telescope after the pre-erection in factory, the contractor has to demonstrate the accuracy of the location of the main telescope axes during operation of the structure, i.e. an elevation rotation angle of 98° and an azimuth rotation angle of 540°.
In particular the following alignment measurements shall be performed by the contractor for the preliminary acceptance of telescope:
according to accuracy specifications for the axes, indicated on fig. No. 1.
The contractor shall provide detailed parts lists of the telescope including all subsystems with mass evaluations, according to a breakdown prepared by the P.O.. Assembly masses shall be measured.
All functional tests shall be performed in the factory for the preliminary acceptance.
The tests which are described in this chapter shall be performed with the completely assembled telescope structure. The following static deformations due to gravity loading shall be measured by the contractors:
Measurements shall be taken at 0°, 30°, 60° and 90° and back to 0° with the same measurement steps. This cycle shall be performed twice.
The measurement accuracy shall be better or equal than ( 0.05mm.
For preliminary acceptance of the telescope after pre-erection in factory a dynamic response test of the structure shall be performed by the LBT P.O..
The purpose of the test is to measure the dynamic response (locked rotor resonance as well as higher resonances) in the open loop condition for the current loop of the telescope motors.
The verification of the lowest locked and free resonance frequencies can be done in the following way:
Excitation of the telescope axes with an electrical noise signal on the torque command input of the amplifiers and measuring the response of the telescope axis on the tachometer and by accelerometers. The input signal and response signal are fed to a frequency analyzer which produces a transfer gain and phase plot.
This test shall be performed for both elevation and azimuth drives.
The friction torque of each axis shall be measured.
The balancing of the elevation structure shall be demonstrated in a test for the altitude angles from 0° to 90° in steps of 10° for the following combinations of spiders:
| SPIDER | INSTALL & TEST | DUMMY MASS |
| F/15 Gregorian | Yes | No (only m2+cell) |
| M3 | Yes | No (only M3+cell) |
| Mirror Cover | Yes | No (only cover) |
| F/4 | No | Yes* |
| F/15 Cassegrain | No | No |
| F/25 Inner (G. Rieke) | No | No |
The functionality of the elevation and azimuth jacking systems shall be verified by testing during the Azimuth frame assembly and with the full weight of the telescope.
The following performances of the hydrostatic bearing system shall be performed by the LBT P.O.:
The following performances of the altitude and azimuth telescope drives shall be performed by the LBT P.O. for preliminary acceptance tests of the telescope:
A full load burn-in test shall be performed with both motors and amplifiers.
The following performances of the altitude and azimuth telescope encoders shall be performed for final acceptance of the telescope:
The following performances of the elevation cable drape shall be performed for final acceptance of the telescope:
The following performances of the instrument cable wraps shall be performed for final acceptance of the telescope:
The following functional tests or measurements of the elevation and azimuth brakes shall be performed by the LBT P.O. for preliminary acceptance testing:
The following functional tests or measurements of the elevation and azimuth auxiliary drives shall be performed by the contractor for the preliminary acceptance testing:
The following functional tests or measurements of the elevation locking systems shall be performed by the contractor for the preliminary acceptance testing:
For the verification of the functions of the auxiliary equipment:
an inspection is envisaged by P.O.
The following functional tests of the two M1 covering systems shall be performed for preliminary acceptance of the telescope:
The following functional tests or measurements of the various spiders shall be performed by the contractor for the preliminary acceptance testing:
The following functional tests or measurements of the safety equipment shall be performed by the contractor for the preliminary acceptance testing:
Acceptance Test Review shall be performed at the end of the acceptance tests.
The purpose of the Acceptance Test Review is to scrutinize the results of the previously performed acceptance tests.
The contractor shall predispose the relevant documents and draw up for each test performed the acceptance test certificate, to be signed by the contractor and by the P.O. responsible.