Burster 9235 User manual

In-Line Amplifier for Strain Gauge Sensors
Page 1
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
In-Line-Amplifier for
Strain Gauge Sensors
Model 9235
© 2005 burster
präzisionsmeßtechnik gmbh & co kg
All rights reserved
Edition 22.04.2005
Manufacturer:
burster präzisionsmeßtechnik gmbh & co kg
Talstraße 1 - 5 PO Box 1432
76593 Gernsbach 76587 Gernsbach
Note:
The following information may be amended without prior notice. No part of this document may be
reproduced or processed using electronic systems without prior consent in writing.
burster provides no warranty of any kind with respect to this material, including the implied warranty
of merchantable quality and fitness for purpose.
burster is not liable under any circumstances for errors, incidental damage or consequential loss
sustained in connection with the function or use of this material.

Model 9235
Page 2
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
1-2

In-Line Amplifier for Strain Gauge Sensors
Page 3
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements

Model 9235
Page 4
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements

In-Line Amplifier for Strain Gauge Sensors
Page 5
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
Table of contents
Page
1. General Information
1.1 Safety information................................................................................... 7
1.2 Application .............................................................................................. 9
1.3 Description.............................................................................................. 9
2. Preparations for operation ............................................................................. 11
2.1 Unpcking of device ............................................................................... 11
2.2 Initial operation ..................................................................................... 11
2.3 Supply voltage ...................................................................................... 11
2.4 Pin assignment ..................................................................................... 11
2.4.1 Version with Submin-D-Connectors ......................................... 11
2.4.2 Version with clamps ................................................................. 12
2.5 Grounding and potential bonding ......................................................... 13
2.6 Function test ......................................................................................... 13
2.7 Checking / Calibration interval.............................................................. 14
2.8 Mounting............................................................................................... 14
2.9 Storage ................................................................................................. 14
3. Operation elements ......................................................................................... 11
3.1 Side wall ............................................................................................... 15
3.2 Top ................................................................................................. 15
4. Operation ................................................................................................. 17
4.1 Switch on after storage or blackout ...................................................... 17
4.2 Supply of sensor................................................................................... 17
4.3 Zero point ............................................................................................. 17
4.4 Amplification ......................................................................................... 17
4.5 Sensivity ............................................................................................... 18
4.6 Input reference point............................................................................. 18
4.7 Calibration shunt................................................................................... 18

Model 9235
Page 6
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
Page
5. Calibration and adjustment of the instrument ................................................. 19
5.1 With physical values ................................................................................ 19
5.2 With prescision voltage source................................................................ 19
5.3 With strain gage simulator ....................................................................... 20
5.4 With calibration step ................................................................................ 20
6. Maintenance and customer service .................................................................. 21
6.1 Maintenance ............................................................................................ 21
6.2 Customer service..................................................................................... 21
7. Technical data .................................................................................................... 23
7.1 Measurement specifications .................................................................... 23
8. Appendix .................................................................................................... 25
8.1 Settling of malfuction ............................................................................... 25
8.1.1 Extention cable............................................................................ 25
8.1.2 Mounting of device ...................................................................... 25
8.1.3 Cable route.................................................................................. 25
8.1.4 Sensor installation ....................................................................... 25
8.2 Default settings........................................................................................ 27
8.3 AGeneral information to sensors / sensor data sheets ........................... 27
8.3.1 Measurement voltage.................................................................. 27
8.3.2 Parallel switching of sensors ....................................................... 27
8.4 Explosion protection / Safety barriers...................................................... 27
8.5 SAMPLE -EG-Conformity declaration- ................................................... 28
8.6 SAMPLE -Confirmation acc. to the device safety law- ........................... 29

In-Line Amplifier for Strain Gauge Sensors
Page 7
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
1. General Information
1.1. Safety information
READ THE INSTRUCTION MANUAL CAREFULLY
PRIOR TO USING THE INSTRUMENT !
Attention
_
To reduce the danger of fire and electrical shock, rain and other humidity should be
avoided.
_
To avoid the risk of an electrical shock, please do not open the housing. Repairs and
services must be effected only by qualified and well trained personnel.
Safety measures
Safety
•This instrument works on 15-30 VAC. Please make sure that the operational voltage
of the instrument is equal to the local feeding voltage. Check the power cable prior to
start of operation.
•If any parts or fluids should enter the device please take off the power cable
immediately. Qualified personnel must check the instrument before you operate it the
next time.
•If you do not want to use the device for a longer period of time you should take foff the
power cable. Always pull on the connector, not on the cable.
General
Information

Model 9235
Page 8
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
Aufstellung
•Assure a sufficient airflow so that excessive heat inside the device is avoided.
•Do not place the instrument on surfaces such as carpets or blankets or near
materials such as curtains or wall textiles that could hinder the air circulation.
•Do not place the device near sources of heat such as radiators, hot air outlets
or at places where it is exposed to direct sunlight, light bulbs, excessive dust,
mechanical vibration or impacts
•Keep the device in sufficient distance to other instruments, machines or
installations that are the source to magnetic fields.
•Do not place heavy objects on the devices.
If the device is brought in from a cold to a warm room there might be liquid condensing
in the interior of the device. Please wait a few hours before you operate the
instrument
The necessary law and safety regulations have to be complied with for every
application case. This is valid also for the use of the accessories.
The device serves for signal processing of strain gage sensors. Every other
use is declared as not appropriate.
The device is not meant for unse under safety critical conditions and is not
a safety element in the sense of an appropriate use. The safe and sound
use of this device does imply an appropriate transport, handling, storage,
setup and mounting as well as careful operation and maintenance.
General
Information

In-Line Amplifier for Strain Gauge Sensors
Page 9
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
1.2 Applikation
Inpracticalapplicationsitoftentimesbecomesnecessarytotransformthemeasuring
signal of a sensor in the most simple way to a standard signal in the sensor’s nearby
environment. This makes a transfer of the measurement values to the central
metrology department or the system’s control easily possible over larger distances
with low losses.
The In-Line-Amplifier offers this function in an ideal way as it is placed in the
connecting cable with the help of wrap connections. Based on its compact and
sturdy construction and its low weight it can be used in almost all applications. Even
movable places of actions that are subject to acceleration forces, e.g. on handling
devices do not pose problems. The device is designed mainly for use outside the
switchboard at almost all places and is configured firmly to one sensor. The
aluminium housing is very stable and offers good protection in rough, industrial
environment.
Users who want to integrate the amplifier on a present board or in another housing
can choose it as an open element with connecting clamps instead of plug contacts.
1.3 Description
The In-Line-Amplifier itself is operated at 15 to 30 V. From this it generates a stable
supply voltage for the sensor. The measuring signals of the sensor that usually
range from 0...5 mV up to 0...10 mV for bridge circuits with strain gages are
amplified to analog 0...10 V.
The values of the sensor are preset roughly by the DIP-switches through an
opening in the housing. The fine tuning of the zero point and amplifier setting is
done with multirange trimmers, accessible with a screw driver through the boring
on the side. The connections of the amplifier are realized by Sub-D-plugs resp.
sockets. Short circuit proof sensor supply and protection against polarity reversal
for the amplifier supply grant extra security. The mounting of the amplifier – if
necessary at all – is realized by clamping or gluing of the housing whereas the open
board has mounting holes for screws of type M 2,5. The limit frequency of the
amplifier is > 1kHz, its weight < 65 g.
General
Information

Model 9235
Page 10
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
Device features
CE-sign
Input and Output protection for all measuring leads and energy lines
Wide input voltage range, protected against polarity reversal
10 V – voltage output
3 sensor values configurable
Connectable sensors: Strain gage bridge circuits 350 Ωto 5 kΩ
Sensor supply: 2,5 V without sense lines
Speed of measurements: Limit frequency 1000 Hz
Precision of measurements: < 0,1 % accuracy
Tare: Zero point configurable in wide range
Calibration shunts: externally connectable
Supply voltage range: 15 ... 30 V DC
Current input: max. approx.10 mA (with connected sensor)
General
Information

In-Line Amplifier for Strain Gauge Sensors
Page 11
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
2. Preparations for operation
2.1 Unpacking of device
Check the device carefully on possible damages. If any discrepancies should be
discovered on the packing or the items, the forwarding agent should be informed
as soon as possible. The packing shall be kept for checking by the representative
or the forwarding agent in such a case.
The transport of 9235 can only be effected in the original packing or a packing of
similar quality.
2.2 Initial operation
Connect the device exclusively to power supplies that are equipped with a safety
transformer in accordance to VDE 0551. Also the sensors, transmitters and
devices that are connected to the signal lines of the 9235 must be equipped as
such.
2.3 Supply voltage
Supply voltage: 15-30 VDC unregulated
Power input: approx. 0.45 VA
2.4 Pin assignment
2.4.1 Version with Submin-D-Connectors
Socket (sensor side)
1+SENSOR EXCITATION
3SHIELD (Optional)
5-SENSOR EXCITATION
6+SIGNAL INPUT
9 - SIGNAL INPUT
Preparations
for operation

Model 9235
Page 12
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements Preparations
for operation
Connector
2+SUPPLY VOLTAGE
3NC
5SUPPLY GROUND
7±OUTPUT VOLTAGE
9OUTPUT GROUND
The pins 3.5 are each connected with each other.
Please keep the protection caps for transport use.
Important:
Use only shielded measurement leads. The cable shield is usually not connected
to the sensor housing on burster sensors. The shield of the cable should be
connected to the plug housing which is electrically connected with the amplifier
housing. The cable shield is usually connected via the supply line or the process
instruments to protective ground.
The shield may also be connected with pin 3 from socket and bushing. As a result,
the shield would be on the function ground of model 9235. The potential bondings
of the electronics connected in the measurement chain have to be respected.
Note: If the shield plug is connected with sensor housing, do not connect with
the plug housing.
Note: The connections of sensor socket pin 3 (shield) and pin 5 (sensor excitation)
as well as the supply resp. process electronics pin 3 (shield), pin 5 (supply ground)
and pin 9 (output ground) are all linked with each other.
2.4.2 Version with clamps
Clamp ”Sensor”
1+SENSOR EXCITATION
2-SENSOR EXCITATION
3NC
4+SIGNAL INPUT
5-SIGNAL INPUT
Clamps without description
1+SUPPLY VOLTAGE
2SUPPLY GROUND
3NC
4±OUTPUT VOLTAGE
5OUTPUT GROUND
The pins 2 and 3 are connected with each other on both clamps.

In-Line Amplifier for Strain Gauge Sensors
Page 13
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
Important:
Use only shielded measurement cables. The cable shield of burster sensors is
usually not connected to the sensor housing. If you mount the amplifier to a
conductive housing, it is recommended to link the shield directly to the housing. The
housing is then usually connected via the supply or process instrumentation to
protective ground.
Optionally, the cable shields can be connected to the clamps 3 of socket and plug.
The shields are then linked to function ground of model 9235. The potential
bondings of the process instruments in the measuring chain have to be respected.
Note: The connections of sensor connection socket clamp 3 (shield) and clamp 2
(sensor excitation) as well as the supply resp. process electronics pin 3 (shield),
clamp 2 (supply ground) and clamp 5 (output ground) are connected with each
other.
Pin 1 of the clamps is marked. View point is on the adaptive opening of the clamps:
pin 1 is on the left side.
2.5 Grounding and potential bonding
Measuring inputs and outputs are neither divided on potential between one and the
other nor on the supply voltage. The housing is insulated from the electronic and
can only be contacted via the housings of the connectors.
The potential bondings of the sensor, cable shield and process electronics have to
be recognized.
2.6. Function test
The instrument does not feature optical nor acoustical signalers. After the first
switch-on please check (without having sensors or instruments connected) the
voltage on +SUPPLY VOLTAGE. The device is set to 2.5V as standard.
Output Ground
±Output Voltage
Shield (optional)
Supply Ground
+ Supply Voltage
+ Sensor Excitation
- Sensor Excitation
Shield (optional)
+ Signal Input
- Signal Input
Preparations
for operation

Model 9235
Page 14
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
2.7. Checking / Calibration interval
The equipment should be test after approximately 2-3 years by the manufacturer.
This interval can be enormous extented, if the instrumentation charakteristics are
not fully used.
2.8 Mounting
It is recommended that the device is not mounted in close proximity to guards or
similar installations or components that can cause electromagnetic fields.
Do not lay the measuring cable parallel to the high power or control lines. If this is
not possible please protect the measuring cable e.g. with strong steel tubes or keep
a minimum distance of 0.5 m. High power and control cables should be twisted (15
twists per meter.
Please note that for mounting on conductive ground that the cable shield can be
linked to the housing additionally. It is important to check the potential bonding.
The board version features 4 borings for screws M 2.5 in a pitch of 40 mm *
37.2 mm.
2.9. Storage
The device must be stored in a dry location at 0...60¡C ambient temperature.
Dew on the device must be avoided. Special measures for start-up after storage
are not necessary.
Preparations
for operation

In-Line Amplifier for Strain Gauge Sensors
Page 15
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
3. Operation elements
3.1 Side wall
Two borings can be found on the side wall through which the potentiometer for fine
tuning of zero point and amplification can be reached.
3.2 Top
Through the boring in the top the switch for setting of the nominal sensitivity can
be reached.
Operation
elements

Model 9235
Page 16
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements

In-Line Amplifier for Strain Gauge Sensors
Page 17
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
4. Operation
4.1 Switch on after storage or blackout
The device is switched on by applying the supply voltage. Warm-up time approx.
10 min.
If the supply voltage is switched off during a running measurement the device
would continue the measurement after the energy is switched back on.
4.2 Supply of sensor
The supply voltage of sensor is asymmetrical, ground related and short-circuit
proof. The maximum current is approx. 10 mA.
4.3 Zero point
The zero point setting is done by setting the potentiometer which can be reached
via a boring on the side wall. The screw driver blades’ width must not be greater
1 mm.
The setup range of the potentiometer is approx. 25% of the measuring range.
4.4 Amplification
The fine tuning of amplification is realized by the settings of a potentiometer which
is reached through the boring in the side wall. The screw driver blades’ width must
not be greater 1 mm.
The setup range of the potentiometer is approx. ±23 % of the measuring range.
Operation

Model 9235
Page 18
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
4.5 Sensitivity
The nominal sensitivity can be chosen via the slide switch.
Nominal Switch 1 Switch 2 Range of
sensitivity up dowen sensitivity low .. high
mV/V mV/V
1zu (rechts) zu (rechts) 0.8 ...1.3
1.5 auf (links) zu (rechts) 1.2 ... 2.0
2auf (links) auf (links) 1.6 ... 2.6
4.6 Input reference point
The input amplifier is designed as a differential amplifier. This means that the
negative signal input is not linked to ground. (If a ground linkage is needed it would
need to be done externally. This is of importance for calibration of voltage sources,
for example)
4.7 Calibration shunt
A calibration shunt can be connected between the clamps 5 and 3 (sensor) resp.
between pins 9 and 5.
Operation

In-Line Amplifier for Strain Gauge Sensors
Page 19
Model 9235
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
5. Calibration and adjustment of the instrument
5.1 With physical values
Application
On all sensors.
Function
Example balance:
The zero point is adjusted on the unburdened balance. Then
the balance is burdened with the known refrerence weight and
the end value is set.
Important note The complete measurement chain is calibrated in this case.
5.2 With precision voltage source
Application
On all sensors.
Function
The sensor is simulated by a precision voltage source. During the calibration the
negative input “SIGNAL INPUT” must be connected to the reference ground
“GROUND”.
Note 1
Please keep in mind that the measurement result is depending on the supply
voltage for strain gage bridge circuit sensors.
Therefore, if a verification of the function of the device with voltage supplying
instruments is required then the sensor supply voltage needs to be measured and
then the calibration voltage has to be calculated, taking this result in consideration
Note 2
The correct function of the sensor cannot be checked with this method.
Calibration
and adjustment

Model 9235
Page 20
In-Line Amplifier for Strain Gauge Sensors
Preparations
for operation
Operation
Calibration
and adjustment
Maintenance and
customer service
Technical
data
Appendix General
Information
Operation
elements
5.3 With strain gage simulator
Application
On strain gage bridge circuit sensors.
Function
A strain gage simulator can be seen as a bridge circuit consisting of precision
resistors which can e.g. simulate the basic settings Zero and
100 % . The strain
gage simulator is connected to replace the sensor.
Note 1
The influence of possible supply voltage differences is corrected here. Typical
calibration error is approx. 0.2%.
Note 2
The correct function of the sensor cannot be checked with this method.
5.4 With calibration step
Application
On strain gage bridge circuit sensors.
he shunt calibration (also: calibration step) should only be applied if all other
methods cannot be used.
Example: At site calibration of a load cell with meas. range 1 MN.
Note: The shunt error of a shunt calibration is typically between 1-5%
due to the calibration method.
Function
The calibration shunt is connected between (-) signal input and (-) supply. This
causes a defined bridge detuning on the strain gage sensors. This results in a
defined calibration step which is the base for the calibration of the measurement
chain. The calibration step can be taken from the test protocol of the sensor
Note
With this method, only the electrical function of the sensor is checked whereas
the characteristics concerning the measurement are not verified.
Calibration
and adjustment