The resonance demodulation technique has been widely used to detect rolling bearing faults based on the signal acquired by piezoelectric accelerometers. However, this method is ineffective in extremely low speed applications due to the instrument limitations of many commercial piezoelectric accelerometers. To alleviate this difficulty, we present a low-frequency resonance accelerometer to capture extremely low speed rolling bearing faults. The design details are reported in this paper. With this new sensor, the resonance demodulation technique can be extended to many low rotational speed applications. This has been demonstrated by two industrial cases: (a) bearing fault detection for a tilting mechanism in a converter mill and (b) monitoring a crossed roller bearing of a bucket wheel staker-reclaimer in a thermal power plant.