Grating type gauge and height difference measuring scale

The invention discloses a grating type gauge and height difference measuring scale, and belongs to the technical field of geometric quantity measurement. The spherical structure is adopted, the influence of rail surface stains and flatness on measurement is reduced through point contact, and the measurement precision is improved; the ruler body is made of a material with a low thermal expansion coefficient, light weight and high strength, so that the ruler is convenient to carry and can meet the measurement requirement in an extreme environment; the grating type length sensor is used, and the measuring axis of the mounting position of the grating type length sensor is the same as the to-be-measured axis, so that the abbe error of length measurement is eliminated, and the gauge measurement precision is improved; the measurement precision of the tilt angle sensor is greatly improved by continuously collecting values of the tilt angle sensor and carrying out trigonometric function calculation by using an average