Hioki DSM-8104 User manual

DIGITAL SUPER
INSTRUCTION MANUAL
DSM-8104
April 2013 Revised edition 1 DS8104A981-01 13-04H
MEGOHMMETER

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Preface
Thank you for purchasing the DSM-8104 and welcome to the growing family of HIOKI’s
Digital Super Megohm Meters/Current Meters.
The DSM-8104 is an insulation resistance meter up to 1000V in measuring voltage.
Incorrect operation of the meter potentially causes an electric shock or damage to a
sample. Please read this manual thoroughly before using the meter and exercise
reasonable caution regarding safety. Keep this manual handy for future reference.
The product has been shipped after minute preshipment inspection by HIOKI.
Nevertheless, please contact our distributor or sales office near your location in case of
a trouble.
I. Product Overview
The Digital Super Megohm Meter DSM-8104 is an insulation resistance meter
embedded with a low-noise voltage source and high-sensitivity ammeter.
The meter has been developed to measure insulating materials of a high resistance
value, capable of measuring resistance within the range of 1 x 103to 3 x 1016Ωand a
current within the range of 30fA to 10mA.
The meter is suitable for measuring insulation resistance of insulating materials with a
large capacity thanks to the low-noise voltage source embedded in the meter.
A liquid crystal display module (240 x 64 dots) of the meter allows easy viewing of
needed information and ease of use.
Principal Features
Measurable voltage range : 0.1 to 1000V
Measurable current range : 30fA to 10mA
Measurable resistance range : 1 x 103to 3 x 1016Ω
Current limiter setting : 5mA, 10mA, 50mA (0.1 to 250V)
: 5mA, 10mA (251 to 1000V)
Integral time setting function : 2ms to 300ms
Trigger delay setting function : 0 to 9999ms
Automatic averaging measurement function
Voltage check function
Contact check function
Self-calibration function
Comparison decision, volume resistivity, surface resistivity computing
functions
Data save and search functions
Histogram display function

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Sequence programming function
Interlock function
GP-IB is a standard provision
Handler interface is a standard provision
RS-232 is a standard provision
II. About This Operational Manual
• Warning, Caution and Notice
Important safety precautions and operational instructions are described in this manual
under the following headings. Strictly follow these precautions and operational
instructions.
[Warning]
Indicates a potentially hazardous situation that could result in an electric
shock or equipment burning.
It is extremely important to strictly follow these instructions to prevent a
hazard.
[Caution]
Indicates a caution that could result in equipment damage.
Operate the meter exercising reasonable caution.
[Notice]
Indicates an important item in operation.

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III. Organizational Elements of Operational Manual
This operational manual has the following chapters. Please make certain to read the
manual carefully before operating the meter.
1. Preparations Before Operation
This chapter contains important information such as a check to be made during
uncrating, operating power supply and measuring cables.
2. Specification
The electrical specification of this meter is described.
3. Operating Principles
This chapter contains the operating principles, block diagram and other information.
4. Names and Functions of Components
This chapter describes the names and functions of keys and characters printed on
the front and rear panels.
5. Preparations for Measurement
This chapter describes the screen of the meter for measurement, settings on the
screen, operating method, methods for indicating measured values and other
matters.
6. Measurement
This chapter describes function settings of the meter, connection of measuring
terminals, and use of measuring jigs and measuring electrodes.
7. GP-IB Interface
This chapter describes control by the GP-IB interface.
8. RS-232 Interface
This chapter describes control by the RS-232 interface.
9. External Interfaces
This chapter describes the handler interface, external trigger input and interlock
input.
10. Maintenance
This chapter describes checks and calibration to be made for safe and reliable use
of this meter.
11. Product Full View
This chapter contains a full view of the product with dimensions.

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IV. Safety Precautions
FOR SAFE USE OF THE METER
• Do the power supply voltage of the meter and commercial power supply voltage to be
supplied match? Please check it. Supplying 200V power supply voltage while the
power supply voltage of the meter is 100V sometimes causes damage to the meter.
• Be certain to ground the grounding terminal on the rear or the grounding rod of the
power cable to the ground.
V. Safety Alert Symbols
！
Warning
symbol This symbol is marked where the operational manual
needs to be referred.
Electrical This symbol indicates high voltage hazard and is
indicated on terminals where high voltage is output
such as measuring terminals.
Grounding
terminal
Indicated on the grounding terminal “GND” on the rear
of the meter. If the grounding pin of the power cable
cannot be grounded, be certain to ground this terminal.
VI. Operational Precautions
Please read this manual thoroughly before operating the meter to correctly handle it.
Strictly follow all the warning, caution and other messages contained in this manual to
prevent accidents and danger.
●Never operate the meter where a combustible gas exists. Otherwise an explosion or
a fire may break out.
●Be certain to ground the grounding pin of the power cable to prevent an accident. If
the grounding pin of the power cable cannot be grounded, be certain to ground the
grounding terminal located on the rear of the meter.
●High voltage up to 1000V is output between the measuring terminals on the panel of
this meter. Do not touch areas where a current is impressed during measurement to
prevent an electrical shock.
●Do not operate the meter in a dusty place or in a place subjected to vibration, direct
sunshine or steam. Otherwise a meter failure may result.
●Supply the power supply voltage specified in the operational manual. Otherwise a
fire or meter damage may result.
●Do not remove the cover of the meter.
Residual voltage sometimes still remains inside the meter after turning the power off
and it is dangerous to touch the inside of the meter. Please contact our sales office
near your location in case of a repair or internal adjustment.
●A cooling fan of a discharge type is installed inside the meter to prevent temperature
rises inside the meter. Poor ventilation of the fan causes meter failures. Provide a
space of more than 10cm behind the fan. Do not place anything on the ventilation
grills on one side and bottom of the meter.

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Contents
1. Preparations Before Operation········································································ 1
1.1 Check during Uncrating·················································································1
1.2 Operating Power Supply················································································1
1.3 Grounding ·····································································································2
1.4 Measuring Cable ···························································································2
1.5 Warming Up Time··························································································2
1.6 Memory Initializing·························································································2
2. Specification
2.1 Measurement Performance············································································3
2.1.1 DC current measurement············································································3
2.1.2 Resistance measurement ···········································································3
2.1.3 Measuring voltage output ···········································································4
2.2 Functional Specification·················································································4
2.2.1 Measuring time···························································································4
2.2.2 Voltage monitoring (Voltage check) ····························································4
2.2.3 Contact check function ···············································································4
2.2.4 Self-calibration function and self-diagnosis function····································5
2.2.5
Comparison measurement and deviation/percent measurement functions ·············5
2.2.6 Measurement (jig setting and data processing) function······························5
2.2.7 Measuring sequence program·····································································5
2.2.8 Storage and display functions of measured data·········································6
2.2.9 Operability and display ···············································································6
2.2.10 Resume function·······················································································6
2.2.11 Input and output functions (external control interfaces)·····························6
2.3 General Specifications···················································································7
2.4 Options··········································································································8
2.4.1 Special options···························································································8
2.4.2 Common options ························································································8
3. Operating Principles
3.1 Operating Principles······················································································9
3.2 Block Diagram·····························································································10
4. Names and Functions of Components
4.1 Safety Alert Symbols ··················································································· 11
4.2 Front Panel ·································································································12
4.3 Rear Panel·································································································· 14
4.4 Command/Numeric Input Keys ···································································· 15
4.5 Display Screen···························································································· 18

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5. Preparations for Measurement
5.1 Setting Measuring Conditions······································································ 20
5.1.1 Screen types···························································································· 22
5.1.2 Setting measuring mode··········································································· 28
5.1.3 Setting measuring voltage········································································ 28
5.1.4 Setting current limiter ··············································································· 29
5.1.5 Setting measuring range ·········································································· 30
5.1.6 Setting integral time (sampling time)························································· 31
5.1.7 Setting averaging function········································································ 32
5.1.8 Setting trigger mode················································································· 32
5.1.9 Creating a program ·················································································· 33
5.1.10 Setting measured data buffer function ···················································· 35
5.1.11 Setting operating environment································································ 37
5.1.12 Setting other items ················································································· 38
5.2 Display and Processing of Measured Value················································· 40
5.2.1 Displaying measured value······································································· 40
5.2.2 Comparison measurement········································································ 42
5.2.3 Deviation display······················································································ 43
5.2.4 Creating histogram··················································································· 44
6.Measurement
6.1 Functions of and Connecting Measuring Terminals······································ 47
6.1.1 Functions of measuring terminals····························································· 47
6.1.2 Connecting measuring terminals ······························································ 48
6.2 Measuring Parts and Circuits······································································· 50
6.2.1 Using measuring jigs················································································ 50
6.2.2 Auto measurement ··················································································· 52
6.2.3 When measuring jig is not used································································ 54
6.2.4 Measurement of circuits ··········································································· 55
6.3 Measuring Planar Sample ··········································································· 55
6.3.1 Measurement by pin terminal···································································· 55
6.3.2 Measurement by electrode for surface resistance measurement··············· 56
6.3.3 Measurement by electrode for planar sample ··········································· 56
6.3.4 Use of shielding box················································································· 58
6.4 Measuring Liquid Sample············································································ 60
6.4.1 Measurement by electrode for liquid sample············································· 60
6.5 Current Measurement·················································································· 62
6.6 Ending Measurement ·················································································· 62
6.7 Measurement Check ··················································································· 63
6.7.1 Voltage check··························································································· 63
6.7.2 Contact check ·························································································· 63

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7. GP-IB Interface
7.1 Overview·····································································································66
7.2 Specification································································································66
7.3 Talker Function ···························································································67
7.4 Response to Query Program Message ························································ 68
7.5 Listener Function························································································· 69
7.6 Device Clear Function ················································································· 70
7.7 Device Trigger Function ··············································································70
7.8 Remote and Local Functions ······································································· 71
7.9 Program Messages······················································································75
7.9.1 List of program messages·········································································75
7.10 Precautions for Listener Specification························································88
7.10.1 Input buffer size······················································································88
7.10.2 Input command message execute and message accept··························88
7.10.3 Command parameter trouble ··································································88
7.10.4 Limit on command message execute ······················································ 88
7.10.5 Output buffer readout ············································································· 88
7.11 Status Byte and Events ·············································································89
7.12 Status Data ·······························································································90
7.13 Status Byte Register··················································································91
7.14 Using Program Message ···········································································93
7.15 Standard Event Status Register·································································96
7.16 Error Register····························································································98
7.17 Device Event Status Register ·································································· 100
7.18 Initialization Value by *RST Message ······················································ 102
8. RS-232 Interface
8.1 Overview··································································································· 104
8.2 Connector Used and Signal Names··························································· 104
8.3 Changeover to GP-IB ················································································ 104
8.4 Connecting Control Signals and Flow Control············································104
8.5 Transmission Data Specification································································ 105
8.6 Reception Data Specification····································································· 106
8.7 Status Byte and Events ············································································· 106
9. External Interface
9.1 Handler Interface······················································································· 107
9.1.1 Handler Interface···················································································· 107
9.1.2 Signal functions······················································································ 108
9.1.3 Electrical characteristics of signals ························································· 110
9.2 External Trigger Terminal·········································································· 112
9.2.1 Connector······························································································· 112
9.2.2 Electrical characteristics········································································· 112
9.3 Interlock Terminal······················································································ 113
9.3.1 Connector······························································································· 113
9.3.2 Electrical characteristics········································································· 113

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9.4 Signal Timing ···························································································· 114
10.Maintenance
10.1 Periodical Checks for Maintenance·························································· 116
10.2 Calibration······························································································· 116
10.2.1 Equipment needed for calibration ························································· 116
10.2.2 Calibration of measuring voltage ·························································· 116
10.2.3 Calibration of current measurement······················································ 116
10.3 Self-calibration Function·········································································· 117
10.4 Self-diagnosis Function··········································································· 118
10.5 Service Organization of HIOKI································································· 119
10.6 Storage and Moving ················································································ 119
11. Product Full View·······················································································120

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1. Preparations Before Operation
1.1 Check during Uncrating
This product has been inspected carefully at the HIOKI factory in preshipment inspection.
Nevertheless, check the following items when uncrating the crate.
1)Any damage on the exteriors of the product.
2)Quantities of accessories
Check in accordance with Table 1.1 List of Accessories.
Table 1.1 List of Accessories
Item Quantity Remarks
Power cable 1 Power cable with three poles
and grounding pin
3P-2P
conversion
adapter 1 Changes the 3P plug of the
power cable to a 2P plug
Operational
manual 1 This manual
If any damage or missing accessory is found, please contact our distributor or sales
office near your location.
1.2 Operating Power Supply
This meter is powered by the following power supply.
Power supply voltage 100V ±10%
Change in power supply voltage Factory option other than 100V (115, 220 or 240V)
Power supply frequency 50/60Hz
[Warning]
Before connecting the power plug, check that the AC power supply voltage to be used
matches the voltage specified on the rear panel.
If they do not match, a fire or damage to the meter may result.
[Caution]
Use a 3-conductor power cable conforming to the power supply voltage. A 100V
power cable is supplied with the meter as an accessory. Do not use this accessory
cable with other electric equipment.

2
1.3 Grounding
Be certain to ground the grounding terminal located on the rear of the meter or the
grounding pin of the power cable to prevent an accident such as an electrical shock.
The round pin of the 3P plug attached to the power cable is the grounding pin. Plug the
cable to a plug socket that has a grounding device.
When using the 3P-2P-conversion adapter, be certain to ground the grounding lead wire
from the adapter or the grounding terminal located on the rear of the meter.
[Warning]
Be certain to ground the grounding pin of the power cable to prevent an accident.
If the grounding pin of the power cable cannot be grounded, be certain to ground the
grounding terminal located on the rear of the meter.
1.4 Measuring Cable
1) Low-noise cable
This meter measures a current at a high sensitivity and measured values sometimes
are not stable due to noise generated by the measuring cable.
Use low-noise shielded-conductor cable meeting the specification of HIOKI.
2) Limited length of measuring cable
Depending on the length of the measuring cable, adjustment of the meter is
necessary to correct open values in the contact check function.
The meter was adjusted for use of the measuring cable in the length of 1m during
preshipment inspection of the meter by HIOKI. Please contact our distributor or
sales office near your location if other cable length is intended to be used.
1.5 Warming Up Time
Warm up the meter more than 30 minutes before operating the meter to obtain the
specified performance.
1.6 Memory Initializing
• Memory initializing
1) Press the [F3] key.
If the screen is displayed, the key is in the SAVE Function mode. The key can
perform its function even if the key is not displayed.
2) Press the [MAN. T] (-) key.
3) Press the [ENTER] key.
This completes memory initialization.
The memory can be initialized by this method anytime as long as the meter is shut
down. However, memory initialization also automatically clears data saved by the
save function.
Memory initialization will set the values that were set during preshipment inspection
at the HIOKI factory shown in Table 7.9 “Settings by Factory Preshipment Inspection
and Values Initialized by Message.”

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2 Specification
2.1 Measurement Performance
2.1.1 DCcurrentmeasurement
Current Measurement
Measuring
Range Maximum Indication Resolution Accuracy
10 pA
100 pA
1 nA
10 nA
100 nA
1 µA
10 µA
100 µA
9.9999 pA
99.999 pA
999.99 pA
9.9999 nA
99.999 nA
999.99 nA
9.9999 µA
99.999 µA
0.1 fA
1.0 fA
10 fA
100 fA
1 pA
10 pA
100 pA
1 nA
± (3.0% of rdg + 1.2% of range)
± (1.5% of rdg + 0.6% of range)
± (0.6% of rdg + 0.6% of range)
± (0.4% of rdg + 0.5% of range)
± (0.4% of rdg + 0.5% of range)
± (0.4% of rdg + 0.5% of range)
± (0.4% of rdg + 0.5% of range)
± (0.4% of rdg + 0.5% of range)
1) Measuring time 300ms
2) Temperature range 23 ±5°C, humidity 85% RH or less
3) Mode Self-calibration automatically executed at 1 minute interval
4) Averaging process On
[Remarks]
The resistance measurement accuracy greatly affects the accuracies of voltage
impressed and of current measured. The DSM-8104 specifies only the current accuracy
as a specification. The resistance accuracy is calculated by the following formula
assuming current measurement is a full-scale value. Normally, measured currents are
lower than currents on a full scale and “resistance accuracy > current accuracy” is a
normal value. Refer to 5.1.5 “Setting measuring range.
Resistance accuracy = Current accuracy +
Voltage accuracy Accuracy
(Resistance on full-scale current) (On full-scale current)

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2.1.2 Measuring voltage output
(1) Setting voltage accuracy and resolution
Setting Voltage Range Resolution Accuracy
0.1 to 250.0V
251 to 1000V 100mV 1 V ±( 0.1%+ 150mV ) ±( 0.1%+ 400mV )
(2) Current limiter
Setting Voltage
Range Set Value Total Current Current on Measuring Side Current on Charge Side
0.1 to 250.0V 50mA
10mA
5mA
±50mA
±10mA
±5mA
±5mA
±5mA
±5mA
±45mA
±5mA
±0mA
Charge ON
251 to 1000V 10mA
5mA ±10mA ±5mA ±5mA ±5mA ±5mA ±0mA
0.1 to 250.0V 50mA
10mA
5mA
±50mA
±10mA
±5mA
±50mA
±10mA
±5mA
±0mA
±0mA
±0mA
Charge
OFF
251 to 1000V 10mA
5mA ±10mA ±5mA ±10mA ±5mA ±0mA ±0mA
1) There are power sources for measurement and for charging and currents for
these voltage sources are “total current = current on measuring side + current on
charge side. The power source on the charge side can be set ON and OFF by a
setting.
2) Current setting errors are ±10%.
2.2 Functional Specification
2.2.1 Measuring time Item Setting Range
Delay Time 0 ～ 9999 ms
Averaging Cycles Auto setting
Sampling time setting
power period
2 to 300ms
1 to 15 PLC
2.2.2 Voltage monitoring (Voltage check)
Voltage that is output is measured and is compared with the set voltage. Any deviation
from the specified range is indicated by flashing of the side mark.
2.2.3 Contact check function
Connection of a work is checked by measuring the capacity by an RF signal and contact
is checked by a difference between contact in an open circuit state.
Item Remarks
Capacity range allowed for contact
detection Minimum 0.5pF. More than 1/10 of capacity on jig side.
Capacity offset range on jig side Max. 100pF (0.1pF resolution)
[Notice] This specification is for a measuring cable length of 1m. Readjustment is
needed if the length exceeds 1m. This function cannot be used if the measuring cable
length exceeds 2m.

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2.2.4 Self-calibration function and self-diagnosis function
The self-calibration function and self-diagnosis function are executed by keying the
Execute key or by the Execute command from the interface.
Self-calibration can be executed automatically after setting an interval. Self-diagnosis is
executed automatically when the power is turned on.
Execution items:
Self-calibration: Current range calibration (can be executed automatically)
Self-diagnosis: Current range calibration, memory check
2.2.5 Comparison measurement and deviation/percent measurement functions
Comparison measurement display: “NG” in decision results is indicated by flashing of the
side mark.
An alarm is sounded by a beep tone (GO decision or NO-GO decision).
Deviation/percent measurement display: The unit is indicated by % or in a measuring
mode during measurement.
Reference values can be set within whole measuring ranges.
Description
Comparison method Upper-limit comparison HI GO:
Measured value > upper-limit value
Intermediate comparison IN GO:
Upper-limit value ≥measured value ≥lower-limit value
Lower-limit comparison LO GO:
Upper-limit value > measured value
Calculation method for
Percent Measuring mode (Measured value - reference value) x 100/reference value
Calculation method for
Deviation Measuring mode Measured value - reference value
2.2.6 Measurement (jig setting and data processing) function
Measurement of surface resistivity and volume resistivity.
Surface resistivity and volume resistivity can be measured directly by setting a constant
for a jig (or an electrode).
Set items
Surface resistivity measurement: Outside diameter of inner electrode and inside
diameter of outer electrode
Volume resistivity measurement: Outside diameter of inner electrode and thickness of
sample
Any electrode constant can be set directly.
2.2.7 Measuring sequence program
Up to ten measuring sequence patterns of discharge, charge, measurement and
discharge can be programmed.
Description
Program sequence (1) Discharge 1, (2) charge, (3) measurement (4) discharge 2
Settable patterns 10
Set time range 0.0 ~ 999.9s

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2.2.8 Storage and display functions of measured data
(1) Measured data buffer
Measured data up to 1000 data groups can be sequentially stored.
Up to 1000 most recent data groups are stored and displayed on the
measurement screen.
Note: Stored data is cleared when the power is shut down.
(2) Histogram counter
Measured values are classified into ten types and numbers of data groups are
stored by digitally counting them by a counter. Thresholds are set for the
individual measuring modes and are indicated on the screen in a bar graph.
Thresholds are set within the measuring range.
Note: Stored data is cleared when the power is shut down.
2.2.9 Operability and display
(1) Keyboard
Rubber key switches
Key clicking tone on or off can be selected
Key lock (prevention of malfunction in the Remote mode) on or off can be
selected
(2) Displays
1) Liquid crystal display 240x64dot graphic LCD (30 columns, 8 rows)
Backlight (Yellowish green LEDs)
Character size
Measured result 4 x 2 size
Measuring conditions Full size
Bar graph display
2) High-voltage warning displayRed LED lit if higher than about 30V
2.2.10 Resume function
When the power supply goes off, the set parameters are automatically stored. When the
power is turned on again, the operation is resumed at the set parameters that are
automatically stored, except the voltage impression state.
2.2.11 Input and output functions (external control interfaces)
(1) GP-IB interface
All items that are operated on the panel can be GP-IB controlled.
Measured results comprising 5-digit exponential measured values, comparison
results and check of measured state are sent in one line of data strings.
Responses in 4-digit fixed decimal points or 5-digit integers are sent to query
commands.
(2) Specification of RS-232 interface function
All items that are operated on the panel can be RS-232 controlled.
Measured results comprising 5-digit exponential measured values, comparison
results and check of measured state are sent in one line of data strings.
Responses in 4-digit fixed decimal points or 5-digit integers are sent to query
commands.

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(3) Specification of handler interface function
The interface for measurement by directly operating the meter using the handler
used in measurement.
The communication items and electrical specification are as follows.
• Communication items
Opening and closing of shielding box, key lock of front panel keys, contact
start, measurement start, contact check start, contact check result
measuring voltage on and off, decision results, analog measurement end
measurement computing end, troubles that have occurred.
• Electrical specification
Contact input and output by a photocoupler
Connector product No. is 57RE-40360-730B (DDK)
2.3 General Specifications
General Specifications
HIOKI-specification insulation meter input connector (INPUT)
Black binding post (GND)
Blue binding post (GUARD)
Red binding post (OUTPUT)
Blue binding post (CHARGE)
Operating environment
Temperature 0 to 40°C, humidity 85% RH or less
Power supply voltage
AC 100V ±10% (standard), 115/220/240V ±10% (factory option)
Power supply frequency
50／60Hz
Power consumption
55VA max.
External dimensions (mm)
332 W x 89 H x 450 D
Weight
6.7kg

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2.4 Options
In addition to the standard accessories listed in Table 1.1 List of Accessories, the
following products are available as options for dedicated use with this meter for easy and
expanded uses of the meter and as options that are common to the meters manufactured
by HIOKI.
2.4.1 Special options
The special options for dedicated use with this meter are as follows.
Option Product Name Standard
Measuring lead with test rod 0GE00002
0GE00001 Length 1m, red Length 1m, black
Measuring lead with alligator clip 0GA00007
0GA00008 Length 1m, red Length 1m, black
Interlock connection cable DSM8104F Length 1m
2.4.2 Common options
The options common to all HIOKI insulation meters are as follows.
Option Product Name Remarks
Electrode for planar
sample,Ø50 diameter SME-8310 With changeover switch for surface and volume measurement and interlock*
Electrode for planar sample,
Ø 19.6 diameter SME-8311 Same as above*
Weight electrode SME-8320 For surface and volume resistances,
shielding box used
Shielding box SME-8350 For shielding dielectric trouble*
Electrode for surface
resistance measurement SME-8301 For anti-electrostatic product
Electrode for surface
resistance measurement SME-8302 Electrode spacing 10mm
Electrode for liquid sample SME-8330 Capacity about 25ml, electrode constant
about 500cm
Chip capacitor electrode SME-8360 For chip capacitor
Surface/Volume Resistance
Measurement Electrode SM9001 Surface/Volume Resistance measurement for static prevention floor
material
Standard Resistor SR-2 Calibrating standard resistor for super
insulator meter
*When connecting this meter to an electrode for planar sample (SME-8310 or SME-8311)
or a shielding box (SME-8350), the interlock connecting cable (DSM8104F) is
necessary.

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3 Operating Principles
3.1 Operating Principles
Equipped with a stable measuring voltage source and high-sensitivity current measuring
unit, this meter calculates an insulation resistance value based on measuring voltage
impressed to the work and measured current value. The meter also outputs a current
value and can be used also as a high-sensitivity ammeter embedded with a voltage
source.
The control unit of the meter has a 32bit CPU for calculations of resistance values and
for other functions.
Current-voltage conversion of the current measuring unit is based on current-voltage
conversion of a charge measuring type that integrates input current. This system
features measurement of feeble current with a high accuracy by lengthening the integral
time.
The output of the current-voltage converter is converted into digital data by an A/D
converter and is fed to the memory in the control unit after being isolated by a
photoisolator.
The control unit computes measured data input to the memory and outputs it to the
display screen and interfaces.
The measuring voltage source is a variable voltage source capable of outputting
1000V/10mA and 250V/50mA maximum, supplying stable measuring voltage. The
measuring voltage source of this meter can set a large maximum output current so that
measuring time can be shortened in measuring a sample with a large electrostatic
capacity such as a capacitor by shortening the charging time.
This meter has a dedicated voltage output for charging (charging terminal), which can be
used to precharge the meter before taking measurement to enhance the measuring
throughput.
The measuring voltage output and charge output are separated by a current limiter,
enabling continual measurement without affecting measurement even if a sample on the
charge terminal side is short-circuited.
An isolated handler interface that can be connected directly to a contact signal, a GP-IB
interface conforming to the IEEE-488 standard and an RS-232 interface are available as
external interfaces that are supplied as standard provisions.
The measuring terminals can be changed to guard grounding or to measuring power
grounding by connecting a short bar on the panel.
The meter can be used as an independent ammeter by measuring a current between the
“INPUT” and “GUARD” terminals. In this case, however, measuring voltage is output on
start of measurement and a minimum value needs be set as measuring voltage.

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3.2 Block Diagram