Hundreds of thousands of concrete bridges and hundreds of billions of tons of concrete require characterization with time for corrosion. Accordingly, protocols for rapid testing and improved field characterization systems that automatically triangulate electrical resistivity and half-cell corrosion potential measurements would be beneficial allowing discrete/periodic mapping of a structure to be performed as well as addressing testing for asphalt covered concrete. Further, it is the low frequency impedance of rebar in concrete that correlates to corrosion state but these are normally time consuming vulnerable to noise. Hence, it would be beneficial to provide a means of making low frequency electrical resistivity measurements rapidly. Further, prior art techniques for electrical rebar measurements require electrical connection be made to the rebar which increases measurement complexity/disruption/repair/cost even when no corrosion is identified. Beneficially a method of determining the state of a rebar without electrical contact is taught.

Disclosed herein are optical stacks that are stable to light exposure by incorporating one or more UV-blocking layers.

Disclosed herein are optical stacks that are stable to light exposure by incorporating one or more UV-blocking layers.

An integrated circuit includes a bi-directional signal transmission pin connected to a sensing electrode of a salinity sensor, an RF interface which generates operating voltages on the basis of an RF signal received through an antenna, different types of driving signal generators having a structure in which each output terminal is connected to the pin, different types of analog-to-digital converters having a structure in which each input terminal is connected to the pin, and a microcontroller unit which generates a first control signal and a second control signal according to a type of the salinity sensor, in which one of the different types of driving signal generators is enabled based on the first control signal, one of the different types of analog-to-digital converters is enabled based on the second control signal, and the operating voltages are supplied to an enabled signal generator and an enabled analog-to-digital converter.

In certain embodiments, an apparatus includes a sensing element having a capacitance to a first reference voltage. The capacitance is variable as a function of a proximity of an object to the sensing element. The apparatus further includes a sample capacitor connected to the sensing element and control circuitry connected to the sample capacitor. The control circuitry is configured to supply a charge to the sample capacitor and the sensing element and discharge the sensing element. The control circuitry is further configured to provide, in response to the discharge of the sensing element, a signal indicative of the capacitance to the first reference voltage of the sensing element. The control circuitry is further configured to process the signal to detect a change in the capacitance to the first reference voltage as indicative of the proximity of the object to the sensing element.

In certain embodiments, an apparatus includes a sensing element having a capacitance to a first reference voltage. The capacitance is variable as a function of a proximity of an object to the sensing element. The apparatus further includes a sample capacitor connected to the sensing element and control circuitry connected to the sample capacitor. The control circuitry is configured to supply a charge to the sample capacitor and the sensing element and discharge the sensing element. The control circuitry is further configured to provide, in response to the discharge of the sensing element, a signal indicative of the capacitance to the first reference voltage of the sensing element. The control circuitry is further configured to process the signal to detect a change in the capacitance to the first reference voltage as indicative of the proximity of the object to the sensing element.

A resistance measuring device includes an amplifying unit including an amplifier, a first and a second current supply unit, a voltage detection unit, and a controller. The controller controls the voltage detection unit to detect a first output voltage of an output terminal of the amplifier in a state where the current of the first current source flows in a forward direction to a measurement target resistor by controlling the first current supply unit, controls the voltage detection unit to detect a second output voltage of the output terminal of the amplifier in a state where the current of the second current source flows in a reverse direction to the measurement target resistor by controlling the second current supply unit, and calculates a resistance value of the measurement target resistor based on the detected first output voltage and the detected second output voltage.

In described examples, one or more devices include: apparatus including a lens element and a transducer to vibrate the lens element at an operating frequency when operating in an activated state; and controller circuitry. The controller circuitry is arranged to measure an impedance of the apparatus, to determine an estimated temperature of the apparatus in response to the measured impedance, to compare the estimated temperature against a temperature threshold for delineating an operating temperature range of the apparatus, and to toggle an activation state of the transducer in response to comparing the estimated temperature against the temperature threshold.

A test and measurement instrument, such as an oscilloscope, including one or more ports to receive one or more signals from a device under test, a trigger enable logic circuit configured to output a trigger enabled signal when a trigger enable event occurs within the one or more signals, the trigger enable event being a real-time event of the one or more signals, one or more trigger logic circuits configured to generate a plurality of trigger signals when the trigger enable signal is received, each trigger signal being generated when a trigger event occurs within one of the one or more signals, and an acquisition circuit configured to acquire and store data in a memory in response to each of the trigger signals.

Disclosed herein are optical stacks that are stable to light exposure by incorporating one or more UV-blocking layers.