An infrastructure monitoring system and method include multiple communications devices. At least one communications device is coupled to an element of the infrastructure.

Infrastructure monitoring devices, systems, and methods.

The GT-cut quartz resonator resonated by two longitudinal modes and provided with the masses for frequency-temperature characteristics adjustment and frequency adjustment. The frequency-temperature characteristics and the frequency of the GT-cut quartz resonator are adjusted by eliminating the masses. Consequently, the quartz resonator adjusted to the normal frequency and having the excellent frequency-temperature characteristics is attained. Further the GT-cut quartz resonator of small and thin size is attained by making the resonant portion and the supporting portions in one piece by photolithographic technique.

Miniature GT-cut quartz resonator

Technologies for detecting leaks in a fluid distribution system are described herein. Historical leak detection information is received from a sensor in the fluid distribution system and collected in a database. A baseline is determined from the historical leak information. Current leak detection information is then received from the sensor and the probability of a leak in the fluid distribution system is determined based on a difference between the current leak detection information and the baseline.

Detecting leaks in a fluid distribution system

A vibration sensor includes a piezoelectric crystal; and a base having an upper surface and a lower surface, the piezoelectric crystal attached to the upper surface of the base, the base defining a notch in at least one of the upper surface and the lower surface. Another embodiment of a vibration sensor includes a first piezoelectric crystal; a second piezoelectric crystal; a base attached to the first piezoelectric crystal on first side of the base and attached to the second piezoelectric crystal on a second side of the base opposite the first side of the base; a voltage amplifier in electrical communication to the first piezoelectric crystal; and a charge amplifier in electrical communication to the second piezoelectric crystal.

Piezoelectric vibration sensor for monitoring machinery

A piezoelectric transducer adapted for adherence to a sounding board of a musical instrument. The piezoelectric crystal has electrically conductive films on each surface. The first surface film is connected to the output conductor and the entire surface adheres to the insulated surface of a conductive inertial mass that is electrically connected to the second conductor surface of the crystal and to the output conductor shield, or ground reference, to provide self-shielding of the transducer and to obviate need for an additional shielded housing. The crystal-mass combination is then preferably potted in a suitable dipping plastic to form a small inexpensive pickup unit with high quality output which may be readily attached to a vibrating surface, such as a drum or an instrument sounding board.

Shielded piezoelectric acoustic pickup for mounting on musical instrument sounding boards

The resonant frequency of a conventional piezoelectric transducer having predetermined dimensions and a fundamental nodal diameter is reduced while maintaining the overall predetermined diameter and fundamental nodal diameter of the transducer. A method of reducing the resonant frequency of a conventional piezoelectric transducer includes the step of radially slotting the substrate of the transducer.

Shoot Lyle Edward

Papers

Method for reducing the resonant frequency of a piezoelectric transducer