Abstract: Disclosed is a monitoring probe for observing groundwater, which is put into an observation well for observing the groundwater to indicate a position of a fresh water-salt water interface of the groundwater. According to the present invention, both ends of a probe body are separated from an inner circumference of an observation well by a catch preventing portion having a convex curved portion or a dumbbell-shaped portion, so that the probe body can be smoothly moved up and down without being caught by a ground-water inlet port of the observation well, thus providing an exact position of a fresh water-salt water interface.

Abstract: Provided is a sensor for measuring water levels of groundwater and surface water using magnetostriction displacement and multi measurement system for groundwater and surface water by using the same. The sensor includes an outer case having a hollow space therein and extending in a longitudinal direction, a magnetostriction line spaced apart from an inner wall in the hollow space of the outer case to extend in the longitudinal direction, a floating permanent magnet guided along the magnetostriction line to be movable in the longitudinal direction, the floating permanent magnet being changed in position to correspond to a water level; and a transceiver applying a current pulse into the magnetostriction line to receive an elastic wave that is generated while first magnetic fields formed in a circumferential direction of the magnetostriction line by the current pulse crosses a second magnetic fields formed in an axial direction of the magnetostriction line by the permanent magnet.

Abstract: Disclosed is a monitoring probe for observing groundwater, which is put into an observation well for observing the groundwater to indicate a position of a fresh water-salt water interface of the groundwater. According to the present invention, both ends of a probe body are separated from an inner circumference of an observation well by a catch preventing portion having a convex curved portion or a dumbbell-shaped portion, so that the probe body can be smoothly moved up and down without being caught by a ground-water inlet port of the observation well, thus providing an exact position of a fresh water-salt water interface.

Abstract: Provided is a sensor for measuring water levels of groundwater and surface water using magnetostriction displacement and multi measurement system for groundwater and surface water by using the same. The sensor includes an outer case having a hollow space therein and extending in a longitudinal direction, a magnetostriction line spaced apart from an inner wall in the hollow space of the outer case to extend in the longitudinal direction, a floating permanent magnet guided along the magnetostriction line to be movable in the longitudinal direction, the floating permanent magnet being changed in position to correspond to a water level; and a transceiver applying a current pulse into the magnetostriction line to receive an elastic wave that is generated while first magnetic fields formed in a circumferential direction of the magnetostriction line by the current pulse crosses a second magnetic fields formed in an axial direction of the magnetostriction line by the permanent magnet.