Abstract: A system is provided for monitoring foam levels within a vessel wherein one or more chemical reactions or biological growths are occurring. The system includes a resonant sensor positioned outside of the vessel at a position to measure foam level within the vessel, the resonant sensor having an inductive element and a capacitive element and tuned to provide for enhanced sensitivity of changes in local permittivity to resonate.

Abstract: An electro-mechanical eddy current probe having a rotatable sensing head for sensing the wall thickness of and locating local defects in a tube or conduit through which it is passed. The rotatable head includes a radially movable, outward projecting sensing member which is spring-biased into engagement with the interior surface of the tube and which carries an eddy current coil or which actuates either the core of a differential transformer, a strain gauge or a rheostat, each electrically monitored by the probe. The cylindrical probe is centered within the tube by a pair of centering guides at either of its ends. The probe also carries a fixed eddy current coil on its non-rotating body portion for detecting and anticipating locations of particular interest within the tube where the longitudinal movement of the probe should be slowed, such as locations of exterior tube support plates where denting is more apt to occur.

Abstract: Tube plugs in several embodiments are provided for plugging and sealing off a defective tube in a heat exchanger to effect a seal at a location within the tube, spaced away from the tube end. The tube plug includes a deformable cylindrical sleeve member which is placed into the tube end, and has a peripheral shoulder thereon which abuts against the tube end to position an interior tapered portion of the sleeve, adjacent to its other open end, at the desired location of the seal to be formed within the tube, and a hard plug member, having a comating tapered portion, which is either hammered into the sleeve or tightened and pulled outwardly depending upon the direction of the engaging tapered surfaces, to deform the sleeve and form the tube seal in the zone of the tapered surfaces.

Abstract: An electro-mechanical eddy current probe having a rotatable sensing head for sensing the wall thickness of and locating local defects in a tube or conduit through which it is passed. The rotatable head includes a radially movable, outward projecting sensing member which is spring-biased into engagement with the interior surface of the tube and which carries an eddy current coil electrically monitored by the probe. The cylindrical probe is centered within the tube by a pair of centering guides at either of its ends. The probe also carries a fixed eddy current coil on its non-rotating body portion for detecting and anticipating locations of particular interest within the tube where the longitudinal movement of the probe should be slowed, such as locations of exterior tube support plates where denting is more apt to occur.