IET Labs HRRS SERIES Troubleshooting guide

HRRS SERIES
High Resistance
Decade Substituter
User and Service Manual
♦PRECISION INSTRUMENTS FOR TEST AND MEASUREMENT ♦
TEL: [phone] • [phone] • FAX: [phone]
www.ietlabs.com
534 Main Street, Westbury, NY 11590
IET LABS, INC.
Copyright © 2001 IET Labs, Inc.
HRRS im/February, 2001

iii
HRRS Series
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, INCLUD-
ING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTIBILITY OR FITNESS FOR
ANY PARTICULAR PURPOSE.

iv
HRRS Series
Contents
WARRANTY ..........................................................................................iii
Contents ............................................................................................... iv
Figures and Tables .................................................................................... v
WARNING .............................................................................................. vi
CAUTION ............................................................................................... vi
Chapter 1
INTRODUCTION ............................................................................ 1
Chapter 2
SPECIFICATIONS .......................................................................... 2
Chapter 3
INSTALLATION .............................................................................. 4
3.2 Initial Inspection ................................................................... 4
3.2 Installation ............................................................................ 4
3.3 Repackaging for Shipment ................................................... 4
3.4 Storage .................................................................................. 5
Chapter 4
OPERATION .................................................................................... 6
4.1. Connection ............................................................................ 6
4.1.1 General Considerations ................................................. 6
4.1.2 Electrical Considerations .............................................. 6
4.2 Dial Setting ............................................................................ 7
4.3 Environmental Conditions ..................................................... 7
Chapter 5
MAINTENANCE ............................................................................. 8
5.1 Preventive Maintenance ........................................................ 8
5.2 Verificaition of Performance.................................................. 8
5.2.1 Calibration Interval ....................................................... 8
5.2.2 General Considerations ................................................. 8
5.2.3 Procedure ...................................................................... 9
5.3 Schematic and Replacement Parts ......................................... 9
5.4 Troubleshooting .................................................................... 9
5.5 Disassembly, Component Replacement, and Reassembly .... 9
5.5.1 Disassembly .................................................................. 9
5.5.2 Component Replacement .............................................. 9
5.5.3 Reassembly ................................................................... 9

v
HRRS Series
Figures and Tables
Figure 1.1. HRRS Series High Resistance Decade Substituter ................ 1
Figure 2.1 Operating Guide Affixed to Unit ........................................... 3
Figure 5.1 HRRS Series Schematic Diagram ........................................ 10
Table 5.1 Model Reference Codes ......................................................... 11
Table 5.2 Replacement Parts List ........................................................... 11
Table 5.3 Commercial and Government Entity CAGE Codes ............... 12
Figure 5.2 Assembly Diagram ................................................................ 13

vi
HRRS Series
WARNING
OBSERVE ALL SAFETY RULES
‘WHEN WORKING WITH HIGH VOLTAGES OR LINE VOLTAGES.
ELECTRICAL SHOCK HAZARD. DO NOT OPEN CASE.
REFER SERVICING TO QUALIFIED PERSONNEL.
HIGH VOLTAGE MAY BE PRESENT WITH HIGH VOLTAGE OPTIONS.
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.
REMOVE POWER WHEN HANDLING = UNIT.
POST WARNING SIGNS AND KEEP 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.

1
INTRODUCTION
HRRS Series
Chapter 1
INTRODUCTION
The High Resistance Decade Substituter (HRRS Se-
ries) is a family of instruments offering a broad choice
of high range, excellent performance resistance
sources (Figure 1.1). High resistance value resistors
are made available without sacrificing other electri-
cal properties
The HRRS Series employs state of the art precision
resistors, of various types for high accuracy, high sta-
bility, and low temperature and voltage coefficients
of resistance.
The standard models offer a choice of one to seven
decades. The panels are clearly labeled showing the
step size and maximum voltage limitations for each
decade.
The binding posts are insulated with Kel-F high re-
sistance non moisture absorbing material to ascer-
tain that no leakage occurs between them.
With a resolution as low as 10 Ωand a maximum
available resistance of over 1 TΩ(= 1000 GW = 1000
kMΩ), the HRRS Series may be used for exacting
precision high value resistance applications. Maxi-
mum voltage capacities of 5 kV or higher are avail-
able. See Chapter 2.
Applications include calibration of meters and
meghommeters, checking of electrochemical and bio-
medical sensors and instruments. These instruments
are useful developments tool wherever small currents
and high resistances are required, such as insulation
testing, low power circuits, and high impedance am-
plifiers.
The HRRS series complements the HARS series
which provides resistance steps as low as 1 mΩ. The
units may be rack mounted to serve as components
in measurement and control systems.
Figure 1.1. HRRS Series High Resistance Decade
Substituter

2SPECIFICATIONS
HRRS Series
Chapter 2
SPECIFICATIONS
SPECIFICATIONS
HRRS-F-1-100G(-5KV) 1 T 1 100 G
HRRS-B-2-1M(-5KV) 110 M 2 1 M
HRRS-B-2-10M(-5KV) 1.1 G 2 10 M
HRRS-B-2-100M(-5KV) 11 G 2 100 M
HRRS-B-2-1G(-5KV) 110 G 2 1 G
HRRS-B-2-10G(-5KV) 1.1 T 2 10 G
HRRS-B-3-100K 111 M 3 100 k
HRRS-B-3-1M 1.11 G 3 1 M
HRRS-B-3-10M(-5KV) 11.1 G 3 10 M
HRRS-B-3-100M(-5KV) 111 G 3 100 M
HRRS-B-3-1G(-5KV) 1.11 T 3 1 G
HRRS-B-4-10K 111.1 M 4 10 k
HRRS-B-4-100K 1.111 G 4 100 k
HRRS-B-4-1M 11.11 G 4 1 M
HRRS-B-4-10M(-5KV) 111.1 G 4 10 M
Resolution
(Ω)
No.
of
Decades
Model*
(For 5 kV version add
-5KV where shown.)**
ORDERING INFORMATION
Total
Resistance
(Ω)
Zero Resistance: <3 mΩper decade at dc.
Operating Conditions: 10°C to 23 °C; <50% RH.
Terminals: Two five-way binding posts on 2 special, low leakage,
Kel-F insulating sockets and one metal ground post electrically
connected to the case.
Setting of value:
Standard: 11 positions, "0"-"10"; silver contacts, ceramic dielectric switch.
Single Decade Version See HARS-X data sheet.
OPTIONS
-RM Rack mountable case for standard 19" rack
-K Kelvin type 4-terminal binding posts
-RO Rear outputs
* Replace "B" with "Q" for higher grade accuracy;
replace "B" with "F" for 1% accuracy.
Resolution
(Ω)
No.
of
Decades
Model* Total
Resistance
(Ω)
HRRS-B-5-1K 111.11 M 5 1 k
HRRS-B-5-10K 1.111 1 G 5 10 k
HRRS-B-5-100K 11.111 G 5 100 k
HRRS-B-5-1M 111.11 G 5 1 M
HRRS-B-6-10 11.111 1 M 6 10
HRRS-B-6-100 111.111 M 6 100
HRRS-B-6-1K 1.111 11 G 6 1 k
HRRS-B-6-10K 11.111 1 G 6 10 k
HRRS-B-6-100K 111.111 G 6 100 k
HRRS-B-7-10 111.111 1 M 7 10
HRRS-B-7-100 1.111 111 G 7 100
HRRS-B-7-1K 11.111 11 G 7 1 k
HRRS-B-7-10K 111.111 1 G 7 10 k
Model Dimensions Weight
3 decades 31.2 cm W x 8.9 cm H x 10.2 cm D 1.4 kg
(12.3" x 3.5" x 4.0") (3.0 lb)
4 decades 37.5 cm W x 8.9 cm H x 10.2 cm D 1.6 kg
(14.8" x 3.5" x 4.0") (3.5 lb)
5 decades 1.9 kg (4.0 lb)
6 and 7 43.9 cm W x 8.9 cm H x 10.2 cm D 2.0 kg
decades (17.3" x 3.5" x 4.0") (4.5 lb)
Decade Resistance Accuracy Option** Max Voltage 5 kV Max Temp. Voltage Stability
Resistance Per Step (Per Step) Voltage Coefficient Coefficient
Available ±ppm/°C ±ppm/V ±ppm/year
100 Ω10 Ω±0.01% ±0.03% ±0.1% 2.5 V N 15 0 10
1 kΩ100 Ω±0.01% ±0.03% ±0.1% 8 V N 5 0 10
10 kΩ1 kΩ±0.01% ±0.03% ±0.1% 23V N 5 0 10
100 kΩ10 kΩ±0.01% ±0.03% ±0.1% 70 V N 5 0 10
1 MΩ100 kΩ±0.01% ±0.03% ±0.1% 333 V* 5000 V 5 0 10
10 MΩ1 MΩ±0.03% ±0.1% ±0.5% 1000 V* 5000 V 10 0.2 10
100 MΩ10 MΩ±0.03% ±0.1% ±1% 1000 V* 5000 V 10 0.2 25
1 GΩ100 MΩ±0.1% ±0.2% ±1% 1000 V* 5000 V 25 1.5 100
10 GΩ1 GΩ±0.2% ±0.5% ±1% 1000 V* 5000 V 80 5 500
100 GΩ10 GΩ±0.5% ±1% ±1% 1000 V* 5000 V 80 5 500
1 TΩ100 GΩ±0.5% ±1% ±1% 1000 V* 5000 V 200 5 500
* Subject to maximum of 1000 V (dc + ac peak);
** Traceable to NIST.
Q B F
For convenience to the user, the pertinent specifications are given in an OPERATING GUIDE, shown
in Figure 2.1, affixed to the case of the instrument.

3
SPECIFICATIONS
HRRS Series

4OPERATION
HRRS Series
Chapter 3
INSTALLATION
Minimize handling of the binding post area and es-
pecially the Kel-F insulating washers.
3.3 Repackaging for Shipment
If the instrument is to be returned to IET Labs, con-
tact the Service Department at the number or address,
shown on the front cover of this manual, to obtain a
“Returned Material Authorization” (RMA) number
and any special shipping instructions or assistance.
Proceed as follows:
1. Attach a tag to the instrument identifying the owner
and indicate the service or repair to be accomplished.
Include the model number, the full serial number of
the instrument, the RMA number, and shipping ad-
dress.
2. Wrap the instrument in heavy paper or plastic.
3. Protect the front panel and any other protrusions
with cardboard or foam padding.
4. Place instrument in original container or equally
substantial heavy carton.
5. Use packing material around all sides of instru-
ment.
6. Seal with strong tape or bands.
7. Mark shipping container “DELICATE INSTRU-
MENT,” “FRAGILE,” etc.
3.2 Initial Inspection
IET instruments receive a careful mechanical and
electrical inspection before shipment. Upon receipt,
verify that the contents are intact and as ordered. The
instrument should then be given a visual and opera-
tional inspection.
If any shipping damage is found, contact the carrier
and IET Labs. If any operational problems are en-
countered, contact IET Labs and refer to the war-
ranty at the beginning of this manual. IET Labs will
work with you until you are satisfied that your in-
strument is operating to fulfill the needs of your ap-
plications.
Save all original packing material for convenience in
case shipping of the instrument should become nec-
essary.
3.2 Installation
For a rack mounted model, installation on a 19 inch
rack may be made using the slots in the rack mount-
ing ears. A mounting location that does not expose
the unit to excessive heat is recommended.
For bench models, no installation as such is required,
because this instrument series is not powered. Since
it is a high accuracy instrument, it is recommended
that a bench space be provided that would not ex-
pose it to abuse and keep it protected from tempera-
ture extremes and contaminants.
For all high resistance instruments, it is highly rec-
ommended that they be stored sealed in a plastic bag
or other well sealed environment to minimize any
contamination that would lead to electrical leakage
and degradation of performance.
Keep unit in a sealed environment when
not in use.
Maintain binding post area clean for
minimum electrical leakage.