GenRad 1404 Series Primary Standard Capacitors

Primary Standard Capacitors

Uses:

• Primary Capacitance Standard
• Standard of Dissipation Factor
• Charge Calibration
• dc Current Calibration

The GenRad 1404 Series standard capacitors are the standard of choice in metrology labs, and still used today by National Metrology Laboratories (NMI) around the world.

These capacitors have been designed as primary reference standards of capacitance with which working standards can be compared.

The 1404 Standard Capacitors have also been used as part of a system for generation of low dc currents as seen in the paper Generation of reference dc currents at 1 nA level with the capacitance-charging method.

In combination with an accurately known external resistor, the GenRad 1404 standard capacitors becomes a standard of dissipation factor.

IET Labs continues to manufacture the 1404 Capacitance Standards to the same exacting specifications as GenRad did in 1963.

All critical parts of the plate assembly are made of Invar for stability and low temperature coefficient.

After heat cycling and adjustment, the assembly is mounted in a heavy brass container, which, after evacuation, is filled with dry nitrogen under pressure slightly above atmospheric and sealed.

The container is mounted on an aluminum panel and protected by an outer aluminum case. Each capacitor is subjected to a series of temperature cycles to determine hysteresis, temperature coefficients and to stabilize the capacitance.

More information on the design, frequency characteristics can be found at GenRad Experimenter 1404 Capacitance Standard

Each 1404 Capacitance Standard is then calibrated using an Andeen and Hagerling AH2700A Capacitance Bridge using direct measurements which are calibrated traceable to the SI, through a National Metrology Institute (NIST) with a CMC¹ as good as 5.5 μF/F.

IET Labs can also provide accredited calibration using the GenRad 1620 via transfer measurements using 1404 capacitance standards that are calibrated traceable to the SI, through a National Metrology Institute mainly NRC in Canada with CMC¹ as good as 4.8 μF/F.

See our Capacitance Calibration page for more information on capacitance calibration.

MODELS

GenRad / General Radio 1404-10nF (10,000 pF) Recently Released
GenRad / General Radio 1404-A (1000 pF) Primary Standard Capacitor
GenRad / General Radio 1404-B (100 pF) Primary Standard Capacitor
GenRad / General Radio 1404-C (10 pF) Primary Standard Capacitor

¹See ISO-17025 Scope of Accreditation (A2LA) for our complete list of accredited calibration capabilities.