CT-EW1: Step Calibration Table

Product Details : 

Designed and endorsed by Erhard Wielandt (Institute of Geophysics, Stuttgart University) whose reputation in the field of broadband seismometry is second to none, the CT-EW1 combines mechanical precision with portability and ease of use.

The CT-EW1 is powered by a standard 9V battery (LR22 / 6LR61) located inside the hand held control box. Operation is truly push button style.

The relatively simple looks of the instrument are deceiving, though; a carefully thought out and painstakingly machined mechanism makes sure that the table performs an up-down motion only, with no undesirable amount of tilt- or torque-like motion getting in the way. Since seeing is believing we have added not one, but two high-precision dial gauges (1 μm precision) on opposite table edges so that you can control the precise amount of displacement. Nothing could be more intuitive and more direct. No software involved, no “magic number” conversion factors - just read the amount of displacement off a circular dial.

It is easy to see how the table works for the vertical component. Conventional shake tables have to be tilted 90° for excitation of the horizontal components. CT-EW1 doesn’t work that way (it isn’t a shake table either). Instead, an extension “bridge” is placed on the table, thus translating the up/down motion of the table top into a stepwise tilt excitation of the horizontal components as shown in the sketch.

Technical details for CT-EW1 Step Calibration Table