A desk with tilt-adjustable tops includes a stand frame; a front top mounted to an upper front portion of the stand frame via a front tilt control device; and a rear top mounted to an upper rear portion of the stand frame via a rear tilt control device. The right angle member provides for light wiring to be wire tired or fastened otherwise, to the gapped risers of the tie plates, so that lights are extended from the horizontal length of the right angle member. Alternatively, absence of a motion can be detected and the control interface presented in response to the detection. Attributes of the received electromagnetic signal can be evaluated relative to the transmitted electromagnetic signal to determine a level associated with one or more of the substances of interest. As a result, impact noise when the valve strikes the valve seat is able to be reduced.