Top: 870µm detector response to a wire movement in the focal plane. The first two peaks correspond to the inward and outward movement of the wire aligned in the $\widehat{x}$ direction. The next two peaks are the response to the ŷ direction wire. Bottom: zoom-in on the quiet part of the trace used for noise statistic calculation, followed by a zoom-in on an $\widehat{x}$-wire and ŷ-wire response. The different amplitudes are due to the different polarization alignments.