Documentation grand piano by Gregor Deiss, 1815

Exact surveying establishes a reference for reconstruktion of the instrument and therefore requires utmost exactitude and precision. A first step is visual inspection for planning the proceedings of survey. For the Deiß grand a combination of procedures is used:

tactile measuring using a Faro 7 links 3D scan arm:

- with straight tip for locating tuning, bar and end pins

- with angled tip for components not accessible otherwise

- with ball tip for measuring the case

x-ray tomography for 3D survey of resonance elements (soundboard, ribs, struts, joints)

boriscopic survey (position and basic measuring of struts, traces of tools and work processes, materials)

laserscan of the karyatids

self made measuring rod for a preliminary survey of the internal resonance chamber

Faro scan Arm

Measuring arrangement for tactile surveying of upper surfaces, achieving a tolerance of 0,08 mm. Of particular importance is the exact measuring of bridge pin positions to establish the scale lengths in relation to the soundboard.