A sensing device includes at least one vibration sensor that responds to sensed vibrations. At least one drive-sense circuit is coupled to the vibration sensor, wherein the at least one drive-sense circuit includes: a first conversion circuit configured to convert a receive signal component of a sensor signal corresponding to the at least one vibration sensor into the sensed signal, wherein the sensed signal indicates a change in an electrical characteristic associated with the at least one vibration sensor; and a second conversion circuit configured to generate, based on the sensed signal, a drive signal component of the sensor signal corresponding to the at least one vibration sensor.

A device for measuring a moisture content in soil according to an aspect of the present invention comprises: a conductive wire structure which can be inserted into soil, includes a first and a second conductive wire, and is formed to have a predetermined structure, the first and the second conductive wire being insulatively coated and extending in parallel to and adjacent to each other; a capacitance measurement circuit for measuring the capacitance between the first and the second conductive wire by using an alternating current power source; and a moisture content calculation unit for calculating a moisture content of the soil by using the measured capacitance.

A device for measuring a moisture content in soil according to an aspect of the present invention comprises: a conductive wire structure which can be inserted into soil, includes a first and a second conductive wire, and is formed to have a predetermined structure, the first and the second conductive wire being insulatively coated and extending in parallel to and adjacent to each other; a capacitance measurement circuit for measuring the capacitance between the first and the second conductive wire by using an alternating current power source; and a moisture content calculation unit for calculating a moisture content of the soil by using the measured capacitance.

Provided herein are various embodiments of determining a cation exchange capacity of a rock sample. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises equilibrating the rock sample to a relative humidity, performing a dielectric permittivity measurement on the rock sample at the relative humidity, and determining a cation exchange capacity of the rock sample based on the dielectric permittivity measurement. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises receiving a dielectric permittivity measurement on the rock sample, and determining a cation exchange capacity for the rock sample based on the dielectric permittivity measurement of the rock sample and a relationship between cation exchange capacity and dielectric permittivity measurements for mineral mixtures corresponding to a range of cation exchange capacity values.

Provided is a liquid sensor or the like that is relatively easy to manufacture. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The optical waveguide includes a first pillar portion, a first metal plate, a second pillar portion, and a second metal plate. The first metal plate is embedded in the first pillar portion. The second pillar portion is provided at a position opposing the first pillar portion. The second metal plate is embedded in the second pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element. The first metal plate includes a first reflecting portion that is tilted relative to the first end surface and reflects light toward the second pillar portion. The second pillar portion includes a second end surface that faces the light receiving element. The second metal plate includes a second reflecting portion that is tilted relative to the second end surface and reflects the light from the first metal plate toward the light receiving element.

A probe provides one end of an electrically conductive path with a ground stake defining a second end. The probe is supported on a tip of a cable rotatably supported by a snake, with the snake including a conductor routed toward the ground stake. A spool can optionally be located between the conductor and the ground stake. A voltage source and a current sensor are located upon this electrically conductive path. The current sensor senses current flow between the probe within the underground pipe and the ground stake. Analysis of the current flowing in this electric circuit allows for determining if underground pipe material includes lead, based at least partially on electrical conductivity of pipe segments through which the probe passes. Conductivity data is transmitted between a local processor, such as a smart phone, and a remote processor for analysis, including a prediction as to lead presence in the pipe.

According to at least one aspect of the present disclosure, a method includes applying an alternating current having a frequency at a selected voltage to a sensor, wherein the voltage is applied between a reference electrode and a working electrode of the sensor, varying the frequency of the alternating current between a lower frequency and an upper frequency, measuring an impedance of the sensor between the reference electrode and the working electrode as a function of the frequency of the alternating current, analyzing the measured impedance to determine a total impedance of the sensor and the real and imaginary components of the total impedance at each applied frequency of the alternating current, and characterizing the sensor based on the total impedance at the low frequency end of the sensor and on the real and imaginary components of the total impedances.

According to at least one aspect of the present disclosure, a method includes applying an alternating current having a frequency at a selected voltage to a sensor, wherein the voltage is applied between a reference electrode and a working electrode of the sensor, varying the frequency of the alternating current between a lower frequency and an upper frequency, measuring an impedance of the sensor between the reference electrode and the working electrode as a function of the frequency of the alternating current, analyzing the measured impedance to determine a total impedance of the sensor and the real and imaginary components of the total impedance at each applied frequency of the alternating current, and characterizing the sensor based on the total impedance at the low frequency end of the sensor and on the real and imaginary components of the total impedances.

Capacitive sensors and capacitive sensing data integration for plasma chamber condition monitoring are described. In an example, a plasma chamber monitoring system includes a plurality of capacitive sensors, a capacitance digital converter, and an applied process server coupled to the capacitance digital converter, the applied process server including a system software. The capacitance digital converter includes an isolation interface coupled to the plurality of capacitive sensors, a power supply coupled to the isolation interface, a field-programmable gate-array firmware coupled to the isolation interface, and an application-specific integrated circuit coupled to the field-programmable gate-array firmware.

Embodiments herein relate to oil condition sensing systems and related methods. In a first aspect, an oil condition sensing system is included having a control circuit, a temperature sensor, and a fluid property sensor, wherein the fluid property sensor measures fluid properties including at least dielectric constant and the oil condition sensing system is configured to automatically detect when an oil change event has occurred, record the fluid property sensor data as new baseline fluid property data after an oil change event has occurred, and evaluate the condition of an engine oil based on a comparison with the baseline fluid property data. The oil condition sensing system can be configured to automatically detect the oil change event by evaluating signals from the fluid property sensor and interpret a change in dielectric constant and/or viscosity crossing a threshold value as an oil change event. Other embodiments are also included herein.