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Note for the record: we use two Applied Geomechanics TuffTilt tiltmeters that are fastened to the optics table. Photos below. (They are the high-gain version and the user manual states they have a resolution of <0.0001 degrees and repeatability of <0.0002 degrees, although we take the analog out of each and run it through our signal conditioning box and into the REAL data acquisition computer to be digitized by the NI multifunction card.) ( The rooftop scanner sits on an x-rail tower that is bolted to the table .). so changing the trailer, changes the table, which changes the tower and scanner. The tiltmeter closest to the telescope is the Trans angle and the one closer to the side is the Long angle. To know for sure which angles they are sensing requires looking on the end of the sensor box where the cable feeds in and noticing the sticker that shows neg to pos range of angles and an arrow. The sticker on the Long angle sensor is hidden on the side but we know that it must be since one senses Trans and one senses Long.
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