To provide a simple examination method of buffer capacity of saliva without influence by examiner’s subjectivity and an examination instrument to carry out suitably the examination method, an examination instrument, in which two to ten kinds of chemical liquids each containing a pH indicator having a transition interval within a pH range of 3. The telematics center is provided with data which identifies the motor vehicle from a first database and with data which identifies the mobile radio link from a second database. Accordingly, the sense amplifier can correctly sense an OFF cell using the stabilized bit line precharge voltage. The present application also relates to polymer reaction products that can be obtained by the method, and methods for producing esterases. Another aspect of the invention provides a system and method for coordinating the movement of human workers comprising detecting one or more visual markers within view of a camera worn by the worker, and determine the location of the worker from the stored location of the visual marker within view of the camera. The first controller causes the light emitting element to emit light during a signal light emission period and stop emission of the light during a light emission stop period, and the first controller superposes the base frequency on a signal serving as the coordinate information and causes the light emitting element to emit light during the signal light emission period.