GB411775A - Improvements in and relating to apparatus for indicating the inclination of bore holes and the like - Google Patents

Abstract

411,775. Borehole clinometers. PAAR, W., Palenberg Bez, Aachen, Germany. Jan. 2, 1934, No. 167. [Class 97 (ii).] In a borehole clinometer, the amount of light passing from a source to a light sensitive device is controlled by a gravity operated device in accordance with the inclinatior of the apparatus. In the form shown, light from the lamp b is reflected by mirrors on to a photoelectric cell g. A tube m, rendered opaque from B to A and containing an air bubble and a quantity of liquid transmitting only rays which do not influence the cell g, e.g. a dark red liquid, is arranged in the path of the light so that the amount transmitted depends on the position of the bubble n relative to the opaque part of the tube m. The cell g is electrically connected to an indicating instrument at the top of the borehole. In a modification a metal cone carried by a plumb-line or pendulum is arranged to move over and mask a slot through which light passes from source to cell. Alternatively the cone may carry the light source. In a further modification, particularly for horizontal borehole, light from the source passes through a slit to a pendulous mirror, the position of which determines whether or not the light beam will pass through a slot to the cell.