This week we installed the tiltmeter in the North End Building. The tiltmeter arm is oriented along the main interferometer beam direction, i.e. toward North, and the vacuum chamber is positioned on the West side of the the tower. In figure 1 the position of the tiltmeter in the NEB is marked with a red star. In figure 2 a picture of the tiltmeter position with respect to the North End Tower is shown. 

The vacuum chamber was delivered to the Virgo site on Friday, and vacuum team took care of the transportation up to the NEB.

The main mechanical parts were dismounted in Naples to avoid damages, and were mounted back on the site. Everything went smooth. Attached few pictures of the setup (figure 3-6). The resonance frequency of the arm has been measured to be around 22 mHz. 

The electronics needed to amplify photodiodes was not working properly, so we dismounted it and debugged it together with the electronics crew. The problem was found and solved. 

The cables labeled with "Tiltmeter" (which were still connected to the distribution box since 2019) were connected to the ADC and DAC racks identified by LAPP people. In particular:

- the 3 ADC were connected to the VME ADC7674 board number 17, channels 12, 13 and 14

- the DAC are connected to the  DAQ box number 35, DAC mezzanine number 121, channel number 5,6 and 7

At present, everything is switched on and connected. What is needed is to activate the Acl process to acquire the signals and control the tiltmeter.

The two motors installed (a PI stepper motor to lock the arm and perform the center of mass regulation and an ARUN stepper motor to move a screw and rebalance the arm)  need to be controlled with a Raspberry Pi and Giulio is taking care of the configuration. It will be installed in the rack as soon as the configuration will be completed.

The chamber is not yet under vacuum, and Luca and Riccardo are completing the installation of pumps and controllers to do the vacuum.