Abstract: A system and method for precisely controlling an amount of tilt of a plumb pile or a batter pile without using two surveying instruments or a clinometer. The system for providing operational information to an operator of a pile driver 10 for driving a pile 101 into the ground has first means 14 for obtaining first data of tilt of the pile in a first coordinate system, a second means 16 for converting the first data into a second data in a second coordinate system defined by at least two points Pl, Pr, and display means 17 for displaying the amount of tile in the second coordinate system.

Abstract: A system and method for precisely controlling an amount of tilt of a plumb pile or a batter pile without using two surveying instruments or a clinometer. The system for providing operational information to an operator of a pile driver 10 for driving a pile 101 into the ground has first means 14 for obtaining first data of tilt of the pile in a first coordinate system, a second means 16 for converting the first data into a second data in a second coordinate system defined by at least two points Pl, Pr, and display means 17 for displaying the amount of tile in the second coordinate system.

Abstract: An attaching means composed of a hole or a groove is formed in the leg of a tripod or another member attached to the legs. A support member inserted in the attaching means is so disposed as to extend in a direction from the attaching means to the ground, toward which direction the tripod is liable to overturn. Therefore, overturning of the tripod can be reliably prevented by a simple operation.

Abstract: An optical device capable of measuring a condition such as deflection of a cylindrical body such as utility pole or cylindrical column precisely and rapidly is provided. The optical device has a telescope with a projection plate. The projection plate has a reference scale made of a plurality of full or substantially full circles arranged concentrically about a central axis of the telescope or a plurality of circular arcs arranged symmetrically about the central axis.

Abstract: An attaching means composed of a hole or a groove is formed in the leg of a tripod or another member attached to the legs. A support member inserted in the attaching means is so disposed as to extend in a direction from the attaching means to the ground, toward which direction the tripod is liable to overturn. Therefore, overturning of the tripod can be reliably prevented by a simple operation.

Abstract: An optical device capable of measuring a condition such as deflection of a cylindrical body such as utility pole or cylindrical column precisely and rapidly is provided. The optical device has a telescope with a projection plate. The projection plate has a reference scale made of a plurality of full or substantially full circles arranged concentrically about a central axis of the telescope or a plurality of circular arcs arranged symmetrically about the central axis.

Abstract: A device and a method for measuring the sizes of a remote object, for example, concrete crack, without using a high-place work vehicle or a ladder. An optical apparatus (e.g. a measuring device (10) ) used for this purpose is provided with a telescope (16) having a reticule plate (46) . The reticule plate (46) is provided with a plurality of reference scales (52) used for comparison with the size (W) of the image (C?) of an object (C) projected onto the reticule plate (46). The size of the object can be measured using the size of the object image measured with the reference scales (52) and a distance (a distance from a reference point P0 a to the object) measured with a distance measuring unit (20) of the optical apparatus.

Abstract: A device and a method for measuring the sizes of a remote object, for example, concrete crack, without using a high-place work vehicle or a ladder. An optical apparatus (e.g. a measuring device (10)) used for this purpose is provided with a telescope (16) having a reticule plate (46). The reticule plate (46) is provided with a plurality of reference scales (52) used for comparison with the size (W) of the image (C?) of an object (C) projected onto the reticule plate (46). The size of the object can be measured using the size of the object image measured with the reference scales (52) and a distance (a distance from a reference point P0 to the object) measured with a distance measuring unit (20) of the optical apparatus.