What are single-ended and differential output, and when should they be used?
Applied Geomechanic’s analog tiltmeters offer both single-ended and differential outputs. Single-ended output is a voltage measured with reference to the ground. However, the ground potential is sometimes “noisy.” It can also be the cause of “ground loops” when the ground potential in two places in the circuit is not the same. This can happen with long cable runs when a break in the cable results in a short to earth ground. A differential output generally produces a quieter output signal by inverting the output signal and then using it as a reference for the measurement. Applied Geomechanics 500, 700 and 800 Series tiltmeters all use this technique. By removing the ground as a reference, ground loops and noise carried through the ground are eliminated. However, the magnitude of output voltage is doubled. In other words, if the single-ended voltage output is 1 volt, the differential output will be 2 volts. Likewise, a single-ended scale factor of 1 degree/volt becomes a 0.5 degree/volt
