A current sensor for use with a charged device model (CDM) tester includes an outer conductor and a cylindrical inner conductor. The inner conductor is positioned within a central cylindrical bore of the outer conductor to provide a characteristic transmission line impedance of approximately 50 ohms. A test probe conductor extends from the distal end of the inner conductor and is electrically connected to the inner conductor. An array of self-supporting ceramic chip resistors is radially positioned between the distal ends of the inner conductor and the outer conductor to provide a uniformly distributed resistance between the inner conductor and the outer conductor. When the test probe conductor is applied to a pin of a charged device under test (DUT), a discharge current passes through the resistors and produces a voltage on the inner conductor that is provided as a signal voltage proportional to the discharge current.

Embodiments of the invention include a current sensing device for sensing current in an organic substrate. The current sensing device includes a released base structure that is positioned in proximity to a cavity of the organic substrate and a piezoelectric film stack that is positioned in proximity to the released base structure. The piezoelectric film stack includes a piezoelectric material in contact with first and second electrodes. A magnetic field is applied to the current sensing device and this causes movement of the released base structure and the piezoelectric stack which induces a voltage (potential difference) between the first and second electrodes.

A fiber optic sensor and related method are described, with the sensor including a cross-coupling element in the optical path between a polarizing element and a sensing element, but separated from the sensing element itself; with the cross-coupling element generating a defined cross-coupling between the two orthogonal polarization states of the fundamental mode of a polarization maintaining fiber guiding light from the light source to the sensing element thus introducing a wavelength-dependent or temperature-dependent sensor signal shift to balance wavelength-dependent or temperature-dependent signal shifts due to other elements of the sensor, particularly signal shifts due to the wavelength dependence of the Faraday effect or the electro-optic effect constant.

A sensor head of a test and measurement instrument can include an input configured to receive an input signal from a device under test (DUT), an optical voltage sensor having signal input electrodes and control electrodes or one set of electrodes, wherein the input is connected to the signal input electrodes, and a bias control unit connected to the control electrodes and configured to reduce an error signal or the input signal bias control signal are electrically combined and applied to a single set of electrodes.

There is provided a system for use with a fiber-optic current transducer. The system includes a processing unit configured to transduce a first light signal into a first electrical signal. The processing unit is further configured to transduce a second light signal into a second electrical signal. The processing unit is configured to remove offsets from the first electrical signal and the second electrical signal by forcing the first electrical signal and the second electrical signal to be on the same per unit basis. Furthermore, the processing unit is configured to combine the first electrical signal and the second electrical signal to produce a composite signal, the composite signal being free of the offsets. And the processing unit is further configured to linearize the composite signal to produce an output current indicative of a current flowing in a conductor disposed proximate the FOCT.

Methods, devices and systems are described that can be used to measure small magnetic fields, such as nano-Tesla and sub nano-Tesla magnetic fields. An example magnetometer includes a core having a photonic material that receives and maintains the propagation of polarized light. The magnetometer's cladding includes a polymer-based magneto-optic (MO) material in contact with the core which surrounds at least part of the core. The core and the cladding are configured to allow at least a portion of the polarized light to enter the cladding to interact with the polymer-based MO material in presence of an external magnetic field. Measurements of the light's polarization state after interaction with the polymer-based magneto-optic (MO) material enable a determination of a strength of the magnetic field.

A fiber-optic current sensor includes an opto-electronics module, a sensor head and a connecting fiber connecting the opto-electronics module to the sensor head. The sensor includes a first and a second beam splitter, between which the measuring light runs in two branches. One fiber connector is arranged in each branch, for connecting a cable assembly to the opto-electronics module. The optical path lengths between the two connectors and the second beam splitter are different, such that light waves cross-coupled into an orthogonal polarization mode due to angular misalignment of the connectors become incoherent with the non-cross-coupled waves returning from the sensor head.

An optical sensor assembly that senses current in a secondary electrical cable while sensing voltage in a primary electrical cable. The optical sensor assembly may include a sensor body, a concentrator core for measuring current. The concentrator core may be attached to a first end of the sensor body. The optical sensor assembly may include a plurality of extension arms that extend from the sensor body. The extension arms may include clamping devices on one end that are configured to attach to a first electrical cable. The concentrator core may be configured to at least partially surround a second electrical cable and sense the current from that second electrical cable.

A method and a sensor for measuring a time derivative of an AC current flowing through a measurement object are presented, wherein a Rogowski-Steinhaus-Chattock coil is aligned with the measurement object and at least one partitioning line is drawn into coil turns of the Rogowski-Steinhaus-Chattock coil and minimizes a capacitive coupling of the coil turns of the Rogowski-Steinhaus-Chattock coil among one another and/or to at least one further electrical line by virtue of the fact, that an electrical potential, corresponding to the electrical potential of the colt turns of the Rogowski-Steinhaus-Chattock con is impressed on the at least one partitioning line by means of an active feedback.

A method of increasing accuracy of optical sensors based on generating two sets of light waves having different velocities in the presence of a non-vanishing measurand field within a sensing element of the sensor is described. A defined static bias phase shift is introduced between the two sets of light waves. The sensor converts a total optical phase shift including static bias optical phase shifts and measurand-induced optical phase shifts into anti-phase optical power changes in at least two detector channels. The method includes steps of normalizing the optical power changes after their conversion into electrical detector signals in the two detector channels to reduce effects of uneven intensity or power of the light source and different loss or gain in the detector channels. Further methods, sensors and apparatus for temperature stabilizing such optical sensors and novel sensors are also presented.