High Voltage Testing
High voltage is found in a wide variety of places including power distribution networks, components that detect light or particles (for example photo-multipliers and electron multipliers), components that emit light or particles (such as halogen globes, and cathode ray tubes), transformers, high powered receivers and transmitters, automotive ignition systems as well as in a variety of natural occurring phenomena like lightening and objects that exhibit electrostatic behavior. The use and study of high-voltage is important as it is crucial to the understanding how electricity can be transmitted, a key parameter in power distribution, as well as how components perform under different conditions.
Spectrum digitizers are ideally suited for use in high voltage test systems as they are available with a wide range of sampling rates, bandwidths and resolutions. For example, high voltage impulse testing typically requires large dynamic range and maximum sensitivity. Spectrum offers high-resolution 14 and 16 bit digitizers that can capture and analyze signals that have frequency content going as high as 250 MHz. These high-resolution cards deliver outstanding signal-to-noise ratio's (up to 72 dB) and spurious free dynamic range (of up to 90 dB) so that the smallest signal variations can be detected and analyzed. Furthermore, they have fully buffered front-end circuitry and calibrated gain ranges making it easy to adjust the full scale input range to match the signal being measured. For even higher frequencies 8 bit digitizers are available that offer up to 5 GS/s sampling rates and 1.5 GHz bandwidth.
The digitizers are available in a number of form factors including PCI, PCIe, PXI and LXI. The PCI and PCIe cards can be installed directly in a desk top PC while the LXI instruments can be used with a Notebook or anywhere that you can connect to a local area network (LAN). With large on-board memories (up to 4 Gsamples/card) and advanced streaming and readout modes the digitizers are ideal for capturing long and complex signals. Streaming data from the digitizer to a storage system also allows the archiving of hours of information. Spectrum's SBench 6 software can provide full instrumentation control as well as an easy way to view, store and qualify signals. FFT's are available for frequency domain analysis and parametric calculations can be used to measure key signal characteristics like amplitude, slope, pulse width and more.
Spectrum Product Features
- Fully Buffered Front-End Circuitry
- Single-Ended and Differential Inputs
- On-Board Block Statistics (Peak Detect)
- Individual trigger per channel with spike detect
- Timestamp with GPS/IRIG-B/Radio Clock synchronization
Matching Card Families
- M4i.44xx: 14/16 Bit 500 MS/s to 130 MS/s digitizer
- M4i.22xx: 8 Bit 1.25 GS/s to 5 GS/s digitizer
- M2p.59xx: 16 bit 20 MS/s to 125 MS/s Digitizer
- DN2.4xx: 16 Bit 500 MS/s to 200 kS/s digitizerNETBOX LXI/Ethernet Digitizer
Power Measurements Using Modular Digitizers
Line power measurements are commonly required to evaluate the performance of devices or circuits. Modular digitizers can make these power measurements. Digitizers are voltage responding measurement instruments. They can also measure current using suitable current probes or current shunts.Read more >>
Case Study: digitizerNETBOX for high magnetic fields
The International MegaGauss Science Laboratory is part of the Institute Solid State Physics (ISSP) at the University of Tokyo. The objective of the laboratory is to study the physical properties of solid-state materials (such as semiconductors, magnetic materials, metals, insulators, superconducting materials) as they are subjected to ultra-high magnetic fields. The fields are also used for researching new materials and controlling their phase and functionality. The laboratories pulse magnets can currently generate up to 87 Tesla (T) by non-destructive methods, and from 100 T up to 760 T (currently the world record for the strongest field generated in-doors) by a destructive process.Read more >>
Signal Processing for Digitizers
Modular digitizers allow accurate, high resolution data acquisition that can be quickly transferred to a host computer. Signal processing functions, applied in the digitizer or in the host computer, permit the enhancement of the acquired data or the extraction of extremely useful information from a simple measurement.Read more >>
- Studies into the initiation of lightening events are being made by the Electrical and Computer Engineering Department, Duke University, Durham, North Carolina, United States using an M4i.4451-x8, 500 MS/s, 14-bit Digitizer. A research paper on the topic can be found here
- Power system failures are often related to mechanical deformation in transformer windings. Winding distortion can lead to insulation deterioration which in turn can produce partial discharge and gassing type events. At the Xi’an Jiaotong University, in Xi’an, China, they are using a Spectrum M2i.4912 Digitizer and M2i.6011 AWG to perform Swept Frequency Response Analysis (SFRA) while researching the main causes of transformer failure in high-voltage power systems. IEEE members can read the full story here
- Using an antenna array for non-contact Partial Discharge (PD) detection has become a useful technique for in air-insulated substation (AIS) monitoring. At the State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, China, they are using two synchronized Spectrum M4i.2221-x8 digitizers to simultaneously collect signals from four antenna at a sampling rate of 2.5 GS/s. The white paper here shows time difference localization techniques and how they can be classified as maximum-likelihood (ML) and least squares (LS) estimators.