IET Labs GenRad 1403 Series User manual

¨PRECISION INSTRUMENTS FOR TEST AND MEASUREMENT ¨
Email: inf[email protected]
TEL: [phone] • FAX: [phone]
www.ietlabs.com
IET LABS, INC.
1403 Series
Capacitance Standard
Operation Manual
Copyright © 2022 IET Labs, Inc.
Visit www.ietlabs.com for manual revision updates
1403 im/May 2022

¨PRECISION INSTRUMENTS FOR TEST AND MEASUREMENT ¨
Email: inf[email protected]
TEL: [phone] • FAX: [phone]
www.ietlabs.com
IET LABS, INC.

WARRANTY
We warrant that this product is free from defects in material and workmanship and, when properly used,
will perform in accordance with applicable IET specifications. If within one year after original shipment,
it is found not to meet this standard, it will be repaired or, at the option of IET, replaced at no charge when
returned to IET. Changes in this product not approved by IET or application of voltages or currents greater
than those allowed by the specifications shall void this warranty. IET shall not be liable for any indirect,
special, or consequential damages, even if notice has been given to the possibility of such damages.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED,
INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR
FITNESS FOR ANY PARTICULAR PURPOSE.
i

Safety Symbols
General definitions of safety symbols used on the instrument or in manuals are listed below.
Caution symbol: the product is marked with this symbol when it is necessary for the user to
refer to the instruction manual.
Hazardous voltage symbol: the product is marked with this symbol when high voltage maybe
present on the product and an electrical shock hazard can exist.
Indicates the grounding protect terminal, which is used to prevent electric shock from the
leakage on chassis. The ground terminal must connect to earth before using the product
Direct current.
Alternating current.
Frame or chassis terminal. A connection to the frame (chassis) of the equipment which
normally includes all exposed metal structures.
On supply.
Off supply.
Hot surface. Avoid contact. Surfaces are hot and may cause personal injury if touched.
Disposal
Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC
This product complies with the WEEE Directive (2002/96/EC) marking requirements.
The affixed label indicates that you must not discard this electrical/ electronic product in domestic
household waste.
Product Category: With reference to the equipment types in the WEEE directive Annex 1, this product
is classified as a “Monitoring and Control instrumentation” product.
Do not dispose of electrical appliances as unsorted municipal waste, use separate collection facilities.
Contact your local government for information regarding the collection systems available. If electrical
appliances are disposed of in landfills or dumps, hazardous substances can leak into the groundwater
and get into the food chain, damaging your health and well-being.
When replacing old appliances with new one, the retailer is legally obligated to take back your old ap-
pliances for disposal.
Proposition 65 Warning for California Residents
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.
This product may contain chemicals known to the State of California to cause cancer, birth defects, or
other reproductive harm

SAFETY PRECAUTIONS
The following general safety precautions must be observed during all phases of operation, service, and repair of
this instrument. Failure to comply with these precautions or with specific WARNINGS elsewhere in this manual
may impair the protection provided by the equipment. Such noncompliance would also violate safety standards
of design, manufacture, and intended use of the instrument.
IET Labs assumes no liability for the customer’s failure to comply with these precautions.
If an instrument is marked CAT I (IEC Measurement Category I), or it is not marked with a measurement category,
its measurement terminals must not be connected to line-voltage mains.
The 1403 is an indoor use product.
DANGEROUS PROCEDURE WARNINGS
Comply with all WARNINGS - Procedures throughout in this manual and instructions on the instrument prevent
you from potential hazard. These instructions contained in the warnings must be followed.
CAUTION
• DO NOT Operate in an Explosive Atmosphere
• Do not operate the instrument in the presence of inflammable gasses or fumes
• Operation of any electrical instrument in such an environment clearly constitutes a safety hazard
• Use Caution around live circuits and whenever hazardous voltages > 45 V are present
• Operators must not remove instrument covers
• Component replacement and internal adjustments must be made by qualified maintenance personnel only
• DO NOT substitute parts or modify the instrument
• When working with high voltages; post warning signs, train personnel and keep unauthorized personnel away.
Do not apply any voltage or currents to the terminals of the instrument in excess of the maximum limits
indicated in the specifications section of this manual.
To avoid the danger of introducing additional hazards, do not install substitute parts or perform unauthorized
modifications to the instrument.
Return the instrument to an IET Labs for service and repair to ensure that safety features are maintained in
operational condition.

WARNING
OBSERVE ALL SAFETY RULES
WHEN WORKING WITH HIGH VOLTAGES OR LINE VOLTAGES.
Dangerous voltages may be present inside this instrument. Do not open the case
Refer servicing to qualified personnel
HIGH VOLTAGES MAY BE PRESENT AT THE TERMINALS OF THIS INSTRUMENT
WHENEVER HAZARDOUS VOLTAGES (> 45 V) ARE USED, TAKE ALL MEASURES TO
AVOID ACCIDENTAL CONTACT WITH ANY LIVE COMPONENTS.
USE MAXIMUM INSULATION AND MINIMIZE THE USE OF BARE
CONDUCTORS WHEN USING THIS INSTRUMENT.
Use extreme caution when working with bare conductors or bus bars.
WHEN WORKING WITH HIGH VOLTAGES, POST WARNING SIGNS AND
KEEP UNREQUIRED PERSONNEL SAFELY AWAY.
CAUTION
DO NOT APPLY ANY VOLTAGES OR CURRENTS TO THE TERMINALS OF THIS
INSTRUMENT IN EXCESS OF THE MAXIMUM LIMITS INDICATED ON
THE FRONT PANEL OR THE OPERATING GUIDE LABEL.
iv

Contents
Chapter 1 Introduction ..............................................................................1
1.1 Description of the 1403 Series.............................................................................. 1
Chapter 2 Specifications ...........................................................................2
Speci!cations ................................................................................................................ 2
Chapter 3 Operation ..................................................................................5
3.1 Initial Inspection and Setup .................................................................................. 5
3.2 Connections to Capacitor...................................................................................... 5
3.3 Temperature Coe"cient........................................................................................ 5
3.4 Temperature Cycling............................................................................................. 6
3.5 Design ................................................................................................................... 6
3.6 Environmental Conditions .................................................................................... 6
3.6.1 Operating Temperature ............................................................................... 6
3.6.2 Storage Temperature ................................................................................... 6
3.7 Shipping and Handling ......................................................................................... 6
Chapter 4 Maintenance..............................................................................7
4.1 Preventive Maintenance........................................................................................ 7
4.2 Calibration............................................................................................................. 7
4.2.1 Calibration Interval..................................................................................... 7
4.2.2 General Considerations............................................................................... 7
4.2.3 Calibration Procedure ................................................................................. 7
4.4 Calibration with GenRad 1620 or AH2500A........................................................ 8
4.5 Replaceable Parts List........................................................................................... 9
v

vi

1
1403 Series
1Introduction
Chapter 1
INTRODUCTION
1.1 Description of the 1403 Series
The 1403 Series (Figure 1-1) are stable, labo-
ratory capacitance standards. They are work-
ing and laboratory standards grade. The 1403
units are available in values ranging from
0.001 pF to 1000 pF.
The 1403 Standard Air Capacitors have a low di-
electric constant and excellent frequency response
making them ideal for testing LCR meters at various
frequencies.
Connections are made to the 1403 via two GenRad
874 connectors.
The new 1403-1pF-bnc Standard Capacitor has 2 bnc
connectors to minimize lead stray capacitance.
Figure 1-1: 1403-D Capacitance Standard
Figure 1-2: 1403-1pF-bnc Capacitance
Standard

2
1403 Series
2 Specifications
Chapter 2
SPECIFICATIONS
For convenience to the user, the pertinent speci•cations are given in a label, shown in Figure 2-1 a•xed to the
case of the instrument.
1403-9701 1403-A, 1000 pF
1403-9704 1403-D, 100 pF
1403-9707 1403-G, 10 pF
1403-9711 1403-K, 1 pF
1403-1pF-BNC 1 pF
1403-9714 1403-N, 0.1 pF
1403-9718 1403-R, 0.01 pF
1403-9722 1403-V, 0.001 pF
ORDERING INFORMATION
SPECIFICATIONS
Model Nominal Capacitance Adjustment
Accuracy Maximum Voltage Dissipation Factor
1403-A 1000 pF
±0.1%
700 V peak < 20 x10-6
1403-D 100 pF
1500 V peak
< 20 x10-6
1403-G 10 pF < 30 x10-6
1403-K 1 pF < 20 x10-6
1403-1pF-BNC 1 pF 500 V peak < 20 x10-6
1403-N 0.1pF
1500 V peak
< 20 x10-6
1403-R 0.01 pF ±0.3% < 20 x10-6
1403-V 0.001 pF ±1% < 20 x10-6
Calibration: An certificate of calibration is supplied
with each capacitor traceable to the SI, giving the
measured direct capacitance and Df at
1 kHz, 15 Vac and 23° ±1°C.
Temperature Coefficient of Capacitance:
Typically ±(20 to 40) ppm/°C, between 20°C and
70°C
Stability: Capacitance change is less than 0.05% per
year.
Residual impedance: See equivalent circuit and plot
on page 1
Terminals: Two GR874 coaxial connectors
Two bnc-f connectors for 1403-1pF-BNC
Outer shell of connectors are connected to case
ground to provide complete shielding of the leads.
Mechanical:
Diameter 3.0625 in (78 mm), height 4.875 in (125
mm), over-all.
Net weight: 1 lbs (0.5 kg)
Shipping weight: 4 lbs (1.9 kg)
Figure 2
Percentage change in effective capacitance, with
frequency produced by residual inductance.
(1403-1pF-BNC has the same change as 1403-K)

3
1403 Series
3Specifications
Figure 2-1: Sample label attached to an 1403 unit
Email: inf[email protected] • [phone] • [phone]
www.ietlabs.com
0.1 pF STANDARD REFERENCE CAPACITOR
Model 1403-N
Observe all safety rules when working with high voltages or line voltages.Connect the shield to earth ground in order to maintain
the case at a safe voltage. Whenever hazardous voltages (>45 V) are used, take all measures to avoid accidental contact with
any live components: a) Use maximum insulation and minimize the use of bare conductors. b) Remove power when adjusting
the capacitor. c) Post warning signs and keep personnel safely away.
SN: A2-2204154
1403 lbl/p4/1403-K/02-05-19
Temperature Coefficient of Capacitance: Typically 30 ppm/oC
between 20 oC and 70 oC.
Max Voltage: 1500 V
Terminals: GR874 coaxial connectors, which provide complete
shielding of the leads.
Calibration: The measured value is obtained by a comparison
to a precision better than ±3 ppm with standards traceable to SI.
Stability: Capacitance change is less than 0.05% per year.
Dissipation Factor: < 20 x 10-6 max at 1 kHz and 50% or less
relative humidity.
Formerly manufactured by
GenRad IET LABS, INC.

4
1403 Series
4 Specifications

5
1403 Series
5Operation
Chapter 3
OPERATION
3.1 Initial Inspection and Setup
This instrument was carefully inspected before ship-
ment. It should be in proper electrical and mechanical
order upon receipt.
To provide ready reference to speci•cations, a label,
shown in Figure 2-1, is attached to the case of the
instrument.
3.2 Connections to Capacitor
All 1403 capacitors have 2 GR 874 or 2 bnc connec-
tors labeled HI and LO, as shown in •gure 3-1.
Figure 3-1: 1403 capacitor standard with bnc
connectors
Equivalent circuit showing direct capacitance, Cd,
and average values of residual inductance, L, and
terminal capacitances, Caand Cb.
Figure 3-2: Capacitance shunted by leakage
to case
3.3 Temperature Coefficient
Temperature coefficients are typically ±(20 to 40)
ppm/°C.
It is important to consider the TC of the 1403 when
measuring at temperatures other than 23°C.

6
1403 Series
6 Maintenance
3.4 Permittivity Errors
The 1403 series can be used over a wide temperature
range and barometric pressures however it is impor-
tant to understand that both affect the permittivity and
therefore the capacitance.
The change of humidity from dry air to 50%
RH results in a around a 1 ppm change in permittiv-
ity and therefore a negligible change in capacitance.
A change in atmospheric pressure from sea level to
1600 meters, results in a change of around 100 ppm
in permittivity and therefore a significant change in
capacitance.
The paper The Measurement and Uncertainty of Air
Dielectric Capacitors from 1 kHz to 10 MHz pro-
vides extremely useful information on the change of
capacitance vs barometric pressure, relative humidity
and temperature for the 1403 Series Air Capacitors.
https://www.osti.gov/servlets/purl/1504063
IET Labs calibrates the 1403 in it’s facility in West
Roxbury, MA. The approximate elevation is 115 feet
(35 meters) above sea level. Given this elevation the
approximate air pressure is 101000 Pa.
3.5 Design of the 1403
The 1403 is a three-terminal standard air capacitor.
The 1403 with capacitance values < 2 pF use three
plates to make up the capacitor element. A high and
low plate which are separated by guard plate. The
guard plate has an aperture of a specific diameter for
the capacitance required.
Higher capacitance values use a stack of plates to
make up the capacitor element.
All plates are separated by ceramic shoulder washers
which minimize dissipation factor.
Additional information on the design of the 1403 can
be found at;
https://www.ietlabs.com/pdf/GR_
Experimenters/1959/GenRad_Experimenter_Aug-
Sept_1959.pdf
3.6 Environmental Conditions
3.6.1 Operating Temperature
For optimal accuracy, 1403 models should be used
in an environment of 23°C ±1°C. They should be
allowed to stabilize at those temperatures after any
significant temperature variation.
3.6.2 Storage Temperature
The 1403 units should be maintained within the stor-
age temperature range of 0°C to 40°C to retain its
accuracy within the specified limits.
3.7 Shipping and Handling
The 1403 Series should not be exposed to any excessive
shock or temperature extremes.
3.8 Cleaning and Maintenance
A soft cloth and denatured alcohol can be used for cleaning.
A Q-tip and denatured alcohol can be used to clean the
connectors.
No other maintenance is required.

7
1403 Series
7Maintenance
Chapter 4
MAINTENANCE
4.1 Preventive Maintenance
Keep the unit in a clean environment. This will help
prevent possible contamination.
1403’s are packaged in a closed case, which limits the
entry of contaminants and dust into the instruments.
If they are maintained in a clean or air-conditioned
environment, cleaning will seldom be required. In a
contaminated atmosphere, cleaning may be required.
4.2 Calibration
The 1403 units may be employed as stand-alone
instruments or as integral components of a system.
If used as part of a system, they should be calibrated
as part of the overall system to provide an optimum
system calibration.
4.2.1 Calibration Interval
The recommended 1403 Series calibration interval is
twelve (12) months.
The calibration procedure may be carried out by the
user if a calibration capability is available, by IET
Labs, or by a certi!ed calibration laboratory.
If the user should choose to perform this procedure,
then the considerations below should be observed.
4.2.2 General Considerations
It is important, whenever calibrating an 1403 unit, to
be very aware of the capabilities and limitations of
the test instruments used.
Recommended Instruments:
• Andeen and Hagerling AH2500A
or
• IET Model 1620 or 1621 Precision
Capacitance Measurement System (bridge)
It is important to allow both the testing instrument
and the 1403 to stabilize for a number of hours at the
nominal operating temperature of 23OC, and at nomi-
nal laboratory conditions of humidity. There should
be no temperature gradients across the unit under test.

8
1403 Series
8 Maintenance
4.3 Calibration Procedure with
GenRad 1620 or AH2500A/
AH2700A Capacitance Bridge
To calibrate an 1403 unit, proceed as follows:
1. 1403 capacitors with bnc connectors should
have the shield disconnected at the HI termi-
nal to minimize stray capacitance. The shield
on the LO terminal should be maintained.
This connection mimics the connection on the
IET/GenRad 1403 Standard Capacitor.
2. Determine and employ proper metrological
practices.
Allow a confidence band for the uncer-
tainty of the measuring instrument and
setup.
3. Determine the allowable drift limits for the
capacitance reading.
<20 ppm/year
4. Con!rm that the readings fall within these
drift limits, allowing for the uncertainty band.
If the reading falls outside the limits,
it has to be repaired by IET or another
qualified facility

9
1403 Series
9Maintenance
4.4 Replaceable Parts List
There are no replaceable parts on the 1403 Series.
Contact IET Labs at for an RMA should service be
required at:
https://www.ietlabs.com/