KYOWA DPM-900 Series User manual

IM-A-857F January 2018
DYNAMIC STRAIN AMPLIFIER
DPM-900/950 SERIES
INSTRUCTION MANUAL
Copyright © KYOWA ELECTRONIC INSTRUMENTS CO., LTD. All rights reserved.
This Instruction Manual may not be copied or reproduced, in whole or part, without consent of KYOWA.
Generally, company names and trade names described in this Instruction Manual are trademarks or
registered trademarks of the companies.
The contents of the Instruction Manual are subjected to change without prior notice.
For the latest content, please refer to our website.
Thank you for purchasing KYOWA’s product DPM-900/950 series Dynamic
Strain Amplifier.
Read this Instruction Manual carefully in order to make full use of the high
performance capabilities of the product.
Do not use the product in methods other than described in this Manual.

CONTENTS
STANDARD ACCESSORIES ........................................................................................................................ 1
SAFETY PRECAUTIONS ............................................................................................................................. 1
PRIOR TO USE........................................................................................................................................... 1
SAFETY SYMBOLS................................................................................................................................... 1
Informational Notes..................................................................................................................................... 4
Examples of Notations................................................................................................................................. 4
1. PRODUCT OUTLINE ................................................................................................................................ 5
1-1 PRODUCT OUTLINE.......................................................................................................................... 5
1-2 SYSTEM CONFIGURATION............................................................................................................. 6
2. PARTS AND FUNCTIONS......................................................................................................................... 7
2-1 FRONT PANEL..................................................................................................................................... 7
2-2 REAR PANEL ....................................................................................................................................... 9
3. PREPARATION ........................................................................................................................................ 10
3-1 HOW TO SET UP INPUT/OUTPUT INSTRUMENTS .................................................................. 10
3-1-1 Input Instrument.......................................................................................................................... 10
3-1-2 Output Instrument....................................................................................................................... 10
3-2 CONNECTION OF POWER............................................................................................................. 10
3-2-1 AC Power ...................................................................................................................................... 10
3-2-2 DC Power...................................................................................................................................... 10
3-2-3 Grounding......................................................................................................................................11
3-3 INITIAL SETTING .............................................................................................................................11
4. BASIC OPERATION................................................................................................................................ 12
4-1 CONNECTION OF INPUT ............................................................................................................... 12
4-2 CONNECTION OF OUTPUT ........................................................................................................... 13
4-3 TURNING ON AND OFF THE POWER ......................................................................................... 14
4-3-1 Turning ON the Power................................................................................................................. 14
4-3-2 Turning OFF the Power............................................................................................................... 14
4-4 SELECTING MODE .......................................................................................................................... 15
4-5 BASIC BALANCING ......................................................................................................................... 15
4-6 SETTING MEASURING PARAMETERS....................................................................................... 15
4-6-1 Setting an Basic Internal Gain.................................................................................................... 15
4-6-2 Setting Low-pass Filter................................................................................................................ 16
4-6-3 Setting High-pass Filter............................................................................................................... 16
4-6-4 Zero Point Fine Adjustment........................................................................................................ 17
4-6-5 Sensitivity Fine Adjustment ........................................................................................................ 17
5. FUNCTIONS.............................................................................................................................................. 18
5-1 INPUT .................................................................................................................................................. 18
5-2 OUTPUT .............................................................................................................................................. 18
5-3 PREHEATING .................................................................................................................................... 18
5-4 BRIDGE CHECK ............................................................................................................................... 19
5-5 BALANCING ...................................................................................................................................... 20
5-5-1 Balancing Range........................................................................................................................... 20
5-5-2 Balancing ...................................................................................................................................... 20
5-6 MOVING ZERO POINT.................................................................................................................... 20
5-7 INTERNAL GAIN .............................................................................................................................. 21
5-7-1 Setting Internal Gain with Calibration Signal .......................................................................... 21
5-7-2 Setting Internal Gain with TEDS ............................................................................................... 22

5-7-3 Setting Internal Gain with ACTL LOAD .................................................................................. 23
5-8 LOW-PASS FILTER........................................................................................................................... 23
5-9 CALIBRATION SIGNAL .................................................................................................................. 24
5-10 KEY-LOCK ....................................................................................................................................... 24
5-11 OSC SYNCHRONIZATION............................................................................................................ 25
5-12 APPLICATION OF CENTRALIZED CONNECTOR.................................................................. 27
5-13 REMOTE CONTROL...................................................................................................................... 27
5-13-1 Remote Control Signals ............................................................................................................. 28
5-13-2 External Connection .................................................................................................................. 29
5-14 EXCITATION VOLTAGE ............................................................................................................... 30
5-15 TPN/DLT MEASURING MODE （For the DPM-911/951 only）.................................................. 31
6. OPTIONS ................................................................................................................................................... 32
6-1 BRIDGE BOX ..................................................................................................................................... 32
6-1-1 Functions of Bridge Box .............................................................................................................. 32
6-1-2 Models of Bridge Box................................................................................................................... 32
6-1-3 Wiring to Bridge Box................................................................................................................... 33
6-1-4 Shield Conversion Cable N-117 .................................................................................................. 33
6-2 AMPLIFIER STAND FA-1B.............................................................................................................. 34
6-3 EXTENSION CABLE N..................................................................................................................... 34
6-4 NOISE FILTER F ............................................................................................................................... 34
6-5 EXCLUSIVE CARRYING CASE ..................................................................................................... 34
6-5-1 Functions of Exclusive Carrying Case ....................................................................................... 35
6-5-2 Carrier Synchronization between Exclusive Carrying Cases .................................................. 35
7. TROUBLE SHOOTING........................................................................................................................... 36
7-1 DPM-900/950 SERIES CANNOT BE TURNED ON....................................................................... 36
7-2 INITIAL BALANCING IS IMPOSSIBLE ....................................................................................... 36
7-3 NO OUTPUT IS AVAILABLE ........................................................................................................... 37
7-4 INSTABILITY OF THE ZERO POINT ........................................................................................... 38
7-5 LARGE NOISE ................................................................................................................................... 38
8. SPECIFICATIONS ................................................................................................................................... 39
8-1 SPECIFICATIONS ............................................................................................................................. 39
8-2 BLOCK DIAGRAM AND OPERATION PRINCIPLE .................................................................. 41
8-2-1 Block Diagram.............................................................................................................................. 41
8-2-2 Operation Principle ..................................................................................................................... 41
8-3 DIMENSIONAL DRAWING ............................................................................................................. 42
9. APPENDIXES............................................................................................................................................ 43
9-1 BRIDGE CHECK FUNCTION AND RESULT INDICATION...................................................... 43
9-2 LOW-PASS FILTER CHARACTERISTIC ..................................................................................... 44
9-2-1 Low-pass Filter Characteristic ................................................................................................... 44
9-2-2 Response Frequency Characteristic 1 (DPM-911/912/913) ...................................................... 45
9-2-3 Response Frequency Characteristic 2 (DPM-951/952)............................................................. 45
9-3 HOW TO CALCULATE STRAINS .................................................................................................. 46
9-3-1 Method of Calculation Applicable to Strain Gage .................................................................... 46
9-3-2 Correction Required due to the Number of Strain Gage Used ................................................ 47
9-3-3 When using strain gage having gage factor other than 2.00 .................................................... 48
9-3-4 Calculating Methods Applicable to Strain Gage Transducer................................................... 49
9-3-5 Correction Required When an Extension Cable was Used ...................................................... 50
9-4 TROUBLE SHOOTING..................................................................................................................... 51
9-5 E TERMINAL OF INPUT CONNECTOR....................................................................................... 52
9-5-1 E Terminal of DPM-911/912/913................................................................................................. 52

9-5-2 E Terminal of DPM-951/952 ....................................................................................................... 52
9-6 INTERNAL GAIN AND INPUT STRAIN........................................................................................ 53
10. GLOSSARY ............................................................................................................................................. 54

1
STANDARD ACCESSORIES
The DPM-900/950 series Dynamic Strain Amplifier (hereinafter referred to as the DPM-900/950 series)
comes with the following accessories. After unpacking, check to be sure that they are included.
Instruction Manual 1
Simplified instruction manual seal 1
AC power cable (P-25) 1
3p - 2p conversion plug (CM-52) 1
BNC cable (U-59 and U-08) 1 each
Fuses, midget type (1.0 A and 0.5 A) 1 each
Product Warranty 1
SAFETY PRECAUTIONS
The DPM-900/950 series is designed in accordance with “8. SPECIFICATIONS.” Do not use the
DPM-900/950 series in an environment exceeding the specifications. Or, failure of the DPM-900/950
series may result.
PRIOR TO USE
For safe use of the DPM-900/950 series, do not forget to read the “Safety Precautions” prior to use.
Kyowa Electronic Instruments Co., Ltd. assumes no liability for any damages resulting from user’s failure
to comply with the safety precautions.
For safety operation of the DPM-900/950 series, the following symbol mark is used.
Indicates “PROTECTIVE GROUND TERMINAL.”
Be sure to connect the GND terminal to the ground.
However, excludes when grounding with a 3-prong AC power cable.
SAFETY SYMBOLS
For safety operation of the DPM-900/950 series, the following symbol marks are used in the Instruction
Manual.
WARNING
Improper operation of the system may result in death or severe injury of the
operator.
CAUTION
Improper operation of the system may result in injury of the operator and
physical damage of the system.

2
WARNING
Power Supply
To prevent a fire hazard, before connecting the power cable, be sure to check the local line voltage is
matched with the operating voltage specified for the DPM-900/950 series.
Power Cable and Power Outlet
To prevent an electric shock or fire hazard, use the accessory power cable, 3p - 2p conversion plug,
and a power plug with protective ground terminal to the greatest possible extent.
When using 3-prong power cable, use a 3-prong power plug with protective ground terminal.
Operators must be cautioned that use of an extension power cable with no ground conductor disables
the protective ground function.
Read the Instruction Manual first, connect the power cable to the DPM-900/950 series with the
DPM-900/950 series turned OFF and connect the power cable to the power outlet.
Protective Ground
To prevent an electric shock hazard, be sure to ensure protective ground before connecting the power
cable.
If 3p – 2p conversion plug is used, be sure to ground the DPM-900/950 series to the “GND” terminal.
If a 2p flat vinyl power code is used, always ground with optional grounding conductor.
For Electrical Operator Safety
To prevent an electric shock hazard, operators must be cautioned not to cut the protective grounding
conductor or disconnect the GND terminal.
Confirmation of Protective Ground
To prevent an electric shock hazard, if any abnormal matters are found in the protective ground
function, fuse holder, etc., do not operate the DPM-900/950 series. In addition, be sure to check safe
protective ground function before operating the DPM-900/950 series.
External Connection
To prevent an electric shock hazard, ensure the safe protective ground of all concerned instrument and
then, connect the DPM-900/950 series to the measuring object and external devices, PC, etc.
Fuse
To prevent a fire hazard, be sure to use a fuse providing the same rating (current, voltage, type) as
specified for the DPM-900/950 series.
Do not use any fuse other than specified. Do not short-circuit the fuse holder.
Before replacing the fuse, disconnect the power cable from the wall outlet in advance.
Inflammable Gaseous Environment
To prevent fire and explosion hazards, do not operate the DPM-900/950 series where it is exposed to
inflammable gases, inflammable vapors or inflammable dust.
If Any Trouble Occurs
To prevent a fire hazard, if smoke is emitted from the DPM-900/950 series, immediately disconnect
the AC adapter from the receptacle and stop using the DPM-900/950 series.
Maximum Input Voltage Range
The DPM-900/950 series is a measuring instrument specified for strain gage transducers and strain
gages. Do not input high voltage. Or, deteriorated performance and damage of the product may result.

3
CAUTION
After the power OFF, wait more than 5 seconds to power ON again.
If the power switch is repeated turned ON and OFF within 5 seconds, fuse may blow out due to rush
current generated by switching the power ON and the DPM-900/950 series’ reliable function may not be
guaranteed.
Do not use the DPM-900/950 series under excessively high/low temperature.
Use the DPM-900/950 series in the specified operating temperature range -10 to 50ºC.
Use at temperatures exceeding the specified range may lower the performance and cause trouble.
If use under direct sunlight or in a cold place is inevitable, prepare a sunscreen or take proper measures
to keep it warm.
Do not use the DPM-900/950 series under high humidity.
Use in a humid place exceeding the specified range or where it is exposed to splashing water may lower
the performance and cause trouble.
Immediately stop the DPM-900/950 series if operating environment changes abruptly.
Leave the DPM-900/950 series as it is until it becomes adaptable to the environment.
Abrupt change in ambient temperature due to transportation, etc. may cause dew condensation result to
deteriorate its performance and cause trouble.
Do not use the DPM-900/950 series under dusty environment.
If dust is entered into the DPM-900/950 series, performance of the DPM-900/950 series may become
deteriorated. Be sure to keep away from dust not only when operating but also storage.
Take care when operating the DPM-900/950 series at a location with excessive vibration.
If excessive vibration is applied to the DPM-900/950 series, performance of the DPM-900/950 series
may become deteriorated.
Adopt vibration-proof measures such as shock absorber, etc.
Do not use the DPM-900/950 series under poor power condition.
When using the AC power cable, use the DPM-900/950 series within the specified power supply voltage.
Use the DPM-900/950 series in an environment without instantaneous voltage drop or interfering noise.
When using the DC power supply, handle the DPM-900/950 series with utmost care.
Touch the battery terminal by the input/output cable or use the same power supply with the measuring
instrument may cause unexpected trouble. Read “3-2 CONNECTION OF POWER” prior to use.
Do not pull cords and cables.
Lay cords and cables with a certain allowance so that o unreasonable force is applied to the connections.
Pulling or applying unreasonable force may cause trouble or interrupt the measurement.
Preheat the DPM-900/950 series before use.
Preheat the DPM-900/950 series for about 30 to 60 minutes after the power ON.
For using a Rotary Transformer Torque Transducers or Inductance-Type Displacement
Transducer, be sure to set the “Setting Switch 4” on the rear panel to ON. Or, it may cause decreases
in measurement accuracy of the DPM-900/950 series.
Do not install the sensor near the welding machine or measure it near the welding machine.
It may cause various malfunction.
Do not disassemble or remodel.
It may cause electric shock or malfunction. And this product will not be out of warranty

4
NOTATION USED IN THE INSTRUCTION MANUAL
Notational Words
To express strain, “10-6 strain”, “m/m” or “” is used properly.
This Manual uses “” relating to the on-panel indications, and “m/m” when referring to strain in general.
The words suffixed by “*” are explained in “10. Glossary”.
The value converted in SI (the International System units) is given in parentheses after each conventional
expression of a unit.
Informational Notes
Certain notations are used as necessary to attract your attention to information that requires special care
when handling the DPM-900/950 series and to information provided for reference purpose.
Examples of Notations
Essential precautions required when handling the DPM-900/950 series.
NOTE
Reference items required when handling the DPM-900/950 series.
MEMO

5
1. PRODUCT OUTLINE
1-1 PRODUCT OUTLINE
The DPM-900/950 series is a strain amplifier that incorporates an AC excitation voltage. When compared
to a DC type strain amplifier, the DPM-900/950 series generally marks high stability, sensitivity and lower
noise. In addition to these, the DPM-900/950 series provides unique features as follows.
Features
[DPM-900 series]
Allows high accuracy measurement since the DPM-900 series has high S/N ratio.
[DPM-950 series]
 Allows high accuracy measurement by inverter noise reduction effect.
[For both DPM-900 and 950 series]
Easy setting
Just set input strain and output voltage at the time.
 Light weight
Approximately 15% lighter than the conventional amplifier.
Monitor and bar graph meter are standard provision.
Strain signal can be monitored without connecting the output to the voltmeter.
High output
The rated output is ±10 V (twice of the conventional amplifier).
 High stability
The zero point stability of the amplifier is good, it can measure with high accuracy.
TEDS*1 function
When using strain gage transducer with built-in TEDS circuit, the internal gain can be easily set without
referring the Test Data Sheet by pressing the TEDS switch.
ACTL LOAD function
The internal gain can be set with the actual load or external calibrator by enabling the ACTL LOAD
mode.
 Bridge check function
This function checks breaking of wires in the strain gage bridge, and the monitor indicates which wires
are broken.
The conventional amplifier is DPM-700B series.
The words suffixed by “*” in the Instruction Manual are explained in “10. Glossary”.
For TEDS function and operation method of the ACTL LOAD function, read “5-7-2 Setting
Internal Gain with TEDS function” and “5-7-3 Setting Internal Gain with ACTL LOAD.”
MEMO