Last week, and similarly as for SR2, B&K hammer measurements were carried out on the HAM5 suspension cages (SRM SR3 and OFI) to test their structural dynamics. The vibration absorbers were ON during the measurements. For each of them, the accelerometer was mounted on the top of one the cage corner, with the accelerometer axis oriented as X = Long, Y = Transverse and Z = Vertical (sus coordinates). Hammer impulse were given in X and Y directions. Pictures attached are showing SR3 and OFI cages with axis labels, accelerometer position and hammer impulse location.

The X/X and Y/Y transfer functions are plotted in the attachments. All cages have well damped resonances below 150Hz, in each of the directions tested.

1) 2014-05-29_H1SR3  : Results are compared with H1 PR3

2) 2014-05-29_H1SRM : Results are compared with H1 HSTS (SR2 MC1 MC3 PRM)

3) 2014-05-29_H1OFI   : Results are compared with L1 OFI

Results are saved and commited in the svn under :

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/BandK
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR3/BandK
/ligo/svncommon/SusSVN/sus/trunk/OFIS/H1/OFI/BandK

Left to do :
HAM4 : Scraper Baffle
HAM5 : Betsy told me OFI is not in its final position yet so I will take the measurement again for OFI when doors will be open.
HAM6 : OMC