Abstract: In a management system for an attachment state of an attachment object, a sensor capable of detecting a value equivalent to stress of stress loaded, or a predetermined value from which the value equivalent to stress can be calculated, a washer storage unit storing identification information of a sensing washer, and a washer control unit transmitting the value equivalent to stress and the identification information of the sensing washer via a communication unit, are provided in the sensing washer between a bolt and a nut that attach an attachment object to a structural object. A management processing device acquires the value equivalent to stress and identification information of the sensing washer transmitted from the sensing washer, and presents the value equivalent to stress of the sensing washer of the identification information, or a corresponding stress value, as relational information with respect to a reference value stored in a storage unit.

Abstract: An optical member for measuring a concentration, the optical member being capable of measuring with high accuracy from low concentration to high concentration, and the like are provided. Light (P1) emitted from a light source (P) for inspection is refracted at a boundary surface between an emitting surface (11b) of a first optical element (11) and a substance (7) to be measured, the substance circulating in a path (15), by an angle (?2) of refraction depending on the concentration (refractive index) of the substance (7) to be measured. Furthermore, when the light is incident on a second optical element (12), the light is refracted to light (P3) parallel to a reference optical axis (O-O). When the light (P3) is emitted from the second optical element (12) to the outside, the light (P3) is further greatly refracted by magnifying means (16) provided on an emitting surface (12b) of the second optical element (12).

Abstract: A sheet-like ceramic substrate for tip parts is provided which can effectively prevent occurrence of a crack thereof. The ceramic substrate comprises a ceramic sheet 7 having first and second primary dividing grooves 2a and 2b and first and second secondary dividing grooves 3a and 3b formed at mutually corresponding locations of the opposite faces thereof. The depth of the dividing grooves 2a, 2b, 3a and 3b is comparatively small, and while the opposite ends of the first primary dividing grooves 2a and on one face of the ceramic sheet 7 extend to a pair of opposing sides 7b of the ceramic sheet 7, the opposite ends of the second primary dividing grooves 2b on the other face of the ceramic sheet 7 are spaced from the opposing sides 7b, and the opposite ends of the first and second secondary dividing grooves 3a and 3b are spaced from the other pair of opposing sides 7a of the ceramic sheet 7.