The GenRad 1404 Series standard capacitors are the standard of choice in metrology labs, and still used today by standards bodies around the world. These
capacitors have been designed as primary reference standards of capacitance with
which working standards can be compared.
In combination with an
accurately known external resistor, the GenRad 1404 standard capacitors becomes
a standard of dissipation factor
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 and temperature coefficients and to
stabilize the capacitance
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
SPECIFICATIONS
Calibration: A
certificate of calibration that is accredited to ISO-17025 by A2LA is
supplied with each capacitor, giving the measured direct capacitance at 1 kHz
and 23° ±1°C. The measured value is obtained by a comparison to a precision
better than ±1 ppm with working standards whose absolute values are known to an
accuracy of ±5 ppm, determined and maintained in terms of reference standards
periodically measured by the National Institute of Standards and
Technology.
Adjustment Accuracy: The capacitance is adjusted
before calibration with an accuracy of ±5 ppm to a capacitance about 5 ppm above
the nominal value relative to the capacitance unit maintained by the reference
standards.
Stability: Long term drift is less than 20 ppm
per year. Maximum change with orientation is 10 ppm and is completely
reversible.
Temperature Coefficient of Capacitance: 2 ±2
ppm/°C for 1404-A and -B, 5 ±2 ppm/°C for 1404-C, from -20°C to +65°C. A
measured value with and accuracy of ±1 ppm/°C is given on the
certificate.
Temperature Cycling: For temperature cycling
over range from -20°C to +65°C , hysteresis (retraceable) is less than 20 ppm at
23°C.
Dissipation Factor: Less than 10-5 at 1
kHz.
Residual Impedance: See Figure 1 on datasheet for
typical values of internal series inductance and terminal
capacitance.
Max Voltage: 750
V.
Terminals: Two BNC coaxial connectors (legacy locking
G874 coaxial connectors are available). Outer shell of one connector is
ungrounded to permit capacitor to be used with external resistor as a
dissipation factor standard.
Mechanical: Lab-bench
cabinet.
Dimensions: 16.9 cm H x 17.2 cm W x 20.4 cm D
(6.63" x 6.75" x 8").
Weight: 3.9 kg (8.5 lb.) net, 6.4 kg
(14 lb.) shipping.
