A drill string communication system is described. A calculation unit calculates a distance between the first and second detecting positions based on detection signals from the first detecting unit and the second detecting unit at the time when a reference sheet having a known length has been conveyed and a length of reference sheet. ; the ring B is a 3- to 8-membered nitrogen-containing non-aromatic heterocyclic ring etc. A user is then allowed to edit a specific test script located on the centrally located database. A method of forming a pH-sensitive electrode, a method of manufacturing a pH probe, and a method for using a pH probe are also disclosed herein. Information about the classification may be made available for a fee and may allow parties to make better business and regulatory decisions.