Extends current range of Scopes, DMMs and Wattmeters
Use with phase angle meters
BNC, GR, UHF, N, HN and C connectors
Insulated enclosure optional
Traceable to international standards via NIST (USA) and UKAS (UK)
About the Series R Current Viewing Resistor / Coaxial Shunt Resistors
The Series R range are non inductive shunts designed to operate over a wide bandwidth, with both AC and DC power systems, especially where phase angle
and propagation delay is a consideration, crucial during impedance measurements and power calibration systems. Very useful for adding or extending the current range of
Power Analyzers, Wattmeters, Phase Angle Meters, Frequency Response Analyzers and Multimeters.
Using the Series R with phase angle meters allows phase angle
measurement between voltage-voltage, voltage-current or current-current, ideal for phase protection
relays, energy meters and current transformer calibration.
CVR's are rugged high frequency resistors designed to sustain very high peak power and current inputs generated by capacitor banks, pulse generator systems and steady state current loads. Their linear response over a broad frequency band provides an accurate indication of current magnitude free from inductive components. Inherent in CVR design is a coupling between the major electrical parameters of resistance, bandpass, energy capacity and wattage rating. This means we provide a wide ranging series of standard units covering a broad range of specifications.
Although most CVR's are designed primarily for surge current measurements, their rugged construction and their low temperature coefficient resistive elements have made them ideally suited to a number of steady state applications. An average wattage rating applicable to continuous current loading is thus quoted for each resistor series. Care should be taken in circuitry involving either AC or high duty cycle pulse currents that this rating not be exceeded, since CVR damage by overheating can result. If requested we can supply resistors with special construction which will increase the standard wattage rating to a high value depending on the model.
Bandpass of a CVR is essentially flat from DC to an upper limit determined primarily by skin effect in the resistive element. Associated bandpass is based on a measured 10% to 90% risetime response to a step function of current produced by a coaxial line pulse generator. The di/dt of the test pulse exceeded 10^12 amps/sec.
Unless otherwise specified, resistors are supplied with resistance tolerance of ±4% of nominal value. In addition, a Kelvin Bridge determination of its exact resistance, accurate to ±0.2% is supplied with each unit. A wide range of special resistance values for any of our standard units can be supplied.
Case construction of all coaxial CVRs is silverplated brass. Standard output signal connector is BNC with other connectors available. Large coaxial CVRs utilize a high current flange and coaxial threaded stud input connections. Powertek's flat configuration CVRs, the Series W, originally developed for flat plate transmission line installation, are available in a wide range of unit widths and input configurations and have been found to be particularly useful in applications requiring resistors with extreme energy and wattage ratings.
All measurements made using the CVR Series R shunts are traceable to National and International standards; through the measurement standards of Powertek. All CVR series
R shunts are supplied with a certificate of conformance necessary for quality assurance standards such as IEC17025/ISO9001. Independent measurement certification is possible using UKAS, A2LA or Z540/NAVLAP certificate.
Non inductive Co-Axial Current shunt - CVR applications
Pulsed current applications
Current sensing for phase meters
Single phase angle indicators V-A
Three phase phase angle indicators V-A
Cos Phi indicators
Power factor meters
High Frequency Watt Meters
Wideband Power meters
Current transformer calibration
Current probe phase delay
SCR current measurements
Current control of automatic welders
Measure output of automotive alternators
Fault current detection to determine bearing
Wear of Steam Turbine generators
Current detection in detonation systems
Three-phase fault testing in power transmission substations
Fault detection in modulators
Measurement of laser system currents
Chopper current control in electric cars
Circuit breaker testing
SERIES R CURRENT VIEWING RESISTORS SPECIFICATIONS
WIDE BANDWIDTH - HIGH FREQUENCY - ULTRA LOW PHASE SHIFT
Small terminating type CVR available with BNC, GR, UHF, N, HN
and C connectors Other connector options available upon
request Standard connections are the "S" input (8-32 stud
with threaded case) BNC output connector
225 - Watt Hi-Wattage Units - 12 1/4 Inch
Overall Length, 3 3/4 Inch Dia.
The Hi-Wattage model is standard. The wattage's stated are
based on heavy current connections with unconfined mounting.
The case temperature should not exceed 140 degrees F (60 degrees
C). Additionally the Finned Models require 300 Cubic feet
(8.6 cubicmeters) per minute air flow over their cases.
The ambient temperature should not exceed 86 degrees F (30
degrees C). Operation above this temperature the wattage
rating should be derated accordingly.
When ordering specify model number, wattage, output connector
and tolerance Example: R-14,000-20, 225 Watts, BNC, 4%