Refurishing the Anechoic Room: Part 3

This is the latest instalment, Part 3, in the refurbishment of the Large Anechoic Chamber at the ISVR, following on from Part 1 (8 April) and Part 2 (6 May).

The next step was to install frames for the side doors to the chamber...

... and turnbuckles were added to the support beam. These will attach the wires that will make up the trampoline floor.

The floor panels and support poles were removed, leaving the old sockets bolted to the concrete floor. The chamber's concrete floor is below the level of the floor in the corridor and the rest of the building, hence the ladder for access. The old sockets have been retained and these will accept removable poles to support load-bearing floor panels. The load-bearing floor will be level with the corridor floor for step-free access.

Plywood panels were then attached to the frames of the side doors so that the wedges could later be attached.

The installation of the trampoline floor began, starting in one corner, with wire cables attached to the support beam with turnbuckles. Apparently we mustn't call it a trampoline floor, because that will invite visitors to bounce up and down and stretch or break it. We'll have to think of an alternative description...

Wedges continued to be installed on the floor around the old sockets, along with more wire cables for the t?r?a?m?p?o?l?i?n?e? , er, wire-mesh floor (oops). The old sockets will eventually hold new poles to support removable load-bearing floor panels above the mesh floor.

The mesh floor was completed...

... and the wedges were installed around the support beam for the wire-mesh floor. The doors have been fully covered with wedges, as can be seen by comparing the photo below with that above.

The floor panels in the corner of the photo above show how the rigid load-bearing grid floor will be supported above the wire-mesh. The photo below shows more detail of the panels. The new panels will be GRP, and much lighter than the metal grids formerly used, which were very heavy to install or remove. It will be much quicker to add or remove the new panels. As with the previous metal grid panels, the GRP panels will allow us to install as much or as little of the load-bearing floor as we need for any particular test. When all the panels are installed, we will also be able to cover the area with solid wood panels for tests which require a hemi-anechoic room, with a free field above a reflecting plane.

The chamber with its wire-mesh floor is now virtually complete. The load-bearing floor grids have been on order, but lockdowns in China have delayed their delivery. We are expecting them early in July. The chamber cannot be completed until they arrive.

Once the chamber is complete, a full range of qualification tests will be carried out with and without the load-bearing floor to verify compliance with the requirements of the various British, European international and industry standards that we work to. In the meantime, we may use the delay to undertake some snagging with one or two test measurements and set ups that don't need the load-bearing floor, so we can see if there are any obvious problems or difficulties that may need fixing.

The photo below shows the chamber with the wire-mesh floor and all the wedges in place.

We will publish a final update when the removable load-bearing floor grids have been fitted and tested, and the chamber has been qualified and commissioned with and without the load-bearing floor.

Our website shows details of the Large Anechoic Chamber?before refurbishment?and will be updated when the work is complete.

The adjacent Large and Small Reverberation Chambers (the ‘large rev’ and the ‘small rev’) are now back in use. We expect the anechoic chamber to be restored to normal use towards the end of July or beginning of August.

Thanks to ?IAC Acoustics UK who are undertaking the refurbishment, and to John Fithyan and Glen Barber of ISVR Consulting for sharing this selection of photographs.

#isvrconsulting?#isvr?#anechoic?#universityofsouthampton