T&M non-inductive coaxial shunt SDN-414 series high-frequency precision resistor (2 Watt)Sic/GaN wide-bandgap double-pulse Ids measurement

About the SDN series current viewing resistor/non-inductive coaxial shunt

The SDN series is a non-inductive shunt designed to operate over a wide bandwidth and is suitable for AC and DC power systems; it is particularly critical in impedance measurement and power calibration systems where phase angle and transmission delay are considered. It is very useful for adding to or extending the current range of power analyzers, power meters, phase angle meters, frequency response analyzers, and multimeters. When used with a phase angle meter, the SDN series can measure phase angle between voltage-voltage, voltage-current, or current-current, making it well suited for calibration of phase protection relays, electricity meters, and current transformers.

CVRs are rugged high-frequency resistors designed to withstand very high peak power and current inputs generated by capacitor banks, pulse generator systems, and steady-state current loads. Their linear response over a wide frequency band provides an accurate indication of current magnitude without inductive elements. Inherent in CVR design is the coupling among key electrical parameters such as resistance, passband, energy capacity, and power rating. This means we offer a broad family of standard units covering a wide range of specifications.

Power rating

Although most CVRs are primarily designed for surge current measurement, their rugged construction and low-temperature-coefficient resistive elements make them ideal for many steady-state applications. Therefore, an average power rating suitable for continuous current loads is cited for each resistor series. In circuits involving AC or high-duty-cycle pulsed currents, care should be taken not to exceed this rating, as overheating may damage the CVR. If required, we can provide resistors with special constructions that increase the standard power rating to high values depending on the model.

Frequency response

The passband of a CVR is essentially flat from DC to an upper limit, determined primarily by the skin effect in the resistive element. The relevant passband is based on the 10% to 90% rise-time response to a current step function generated by a coaxial-line pulse generator. The di/dt of the test pulse exceeds 10^12 A/s.

Resistance value

Unless otherwise specified, the resistance tolerance is ±4% of the nominal value. In addition, each unit is supplied with an accurate resistance determination by Kelvin bridge, accurate to ±0.2%. We can provide a wide range of special resistance values for any of our standard units.

Mechanical design

All coaxial CVRs have a silver-plated brass housing construction. The standard output signal connector is BNC; other connectors are available. Large coaxial CVRs use high-current flanges and coaxial threaded stud input connections. Powertek's flat-configuration CVRs, the W series, were originally developed for flat-plate transmission line mounting, feature a wide range of unit widths and input configurations, and have been found particularly useful in applications requiring resistors with very high energy and power ratings.

Global traceability

All measurements made with CVR series SDN shunts are traceable to national and international standards through Powertek's measurement standards. All CVR series SDN shunts are supplied with a certificate of conformity required by quality assurance standards such as IEC 17025 / ISO 9001. Independent measurement certification can be provided using UKAS, A2LA, or Z540 / NAVLAP certificates.