An electronic hymnal system comprises a music stand and a hymnal display. The apparatus comprises a series of Bragg gratings, a light guide incorporating the series of Bragg gratings and a plurality of moveable wall portions. The torque limiting element coils around the middle section and contacts the shaft assembly, and is accommodated within the first hollow cylinder. At least one of the two probes in the tank are utilized with the monitor to measure the voltage between the tank and the selected probe.