AD2408F-Strain
Strain Gauge Data Acquisition Module
Strain Gauge Data Acquisition Module
Introduction
The AD2408F-Strain
module is a one of the family of Keynes Controls high speed data
acquisition modules. This unit offers simultaneously sampling on
8 strain gauge channels and uses individual 24 bit
Sigma Delta converters to digitise the input signals.
For distributed operations the AD2408F-Strain module can be
connected into an ATM network in order to maintain high samples rates
and fully synchronised operations. No other network product offers such
high speed acquisitions, with full synchronised readings over
a network.
The AD2408F-Strain
module can also communicate directly to a data logger PC running a
Windows operating system via an RS-422
interface card.
The ATM network enables very precise synchronisation by using a common network clock signal to all devices. All of the interfaces obtain timing information from the same source and so offer high levels of synchronisation without any additional cabling or external systems.
The AD2408F-Strain
module can be supplied to operate with any standard strain gauge.
The AD2408F-
For distributed operations the AD2408F-
The AD2408F-
The ATM network enables very precise synchronisation by using a common network clock signal to all devices. All of the interfaces obtain timing information from the same source and so offer high levels of synchronisation without any additional cabling or external systems.
The AD2408F-
Specification
No. Channels
8 Full
Differential
ADC Type
Stereo 24 Bit Sigma
Delta Converter
using digital anti-alias
filter
using digital anti-
Dynamic Range
> 100 db
Sample Rate
1-48
KHz
Software selectable
Gauge Type
350 Ohm / Standard
1 K / 500 Ohm selectable
1 K / 500 Ohm selectable
Bridge Excitation
Const Curr
8.33
mA @ 350 Ohm
Automatic cable length compensation
Automatic cable length compensation
Bridge Type
full, ½ and ¼ support
User selected in software
User selected in software
Bridge Zero / Balance
Software Operation
No load value recorded and used as offset correction.
No load value recorded and used as offset correction.
Channel Protection
Short Circuit
protected
Resetable fuse
Resetable fuse
Input Impeadence
> 10 MW
Operating Temp
°C
-10
to 50 °C
Storage Temperature
-
20 to 60 °C
Calibration Type
Auto-calibration
by precision DC
reference Global across all
channels modules within an installation
Calibration Points
3 point calibration
-25
mV, 0V and +25 mV
-
Calibration Temp
Sensitivity
5 ppm/°C each
range.
Comms. Port
RS422 Serial port
Max transmission = 10m
18 M baud @ 48KHz/ Channel
Max transmission = 10m
18 M baud @ 48KHz/ Channel
Power Supply
12 -
24V Auto-detect @ 15W
Status LED
1 = Power
2 = Boot-up/Initialisation
3 = Synchronisation
2 = Boot-
Height
Width
Depth
Width
Depth
262 mm
45 mm
220 mm
45 mm
220 mm
Strain Gauge Excitation
Each of the channels are individually protected ensuring that should a sensor become short circuit then it cannot effect the operations of another channel .
The use of const current sensor excitation ensures that automatic sensor cable length compensation is carried as part of the excitation and now allowance need be made for its effect as part of any calibration or post analysis operation.
Data Synchronisation
The AD2408F contains 4 x stereo 24 bit Sigma Delta converters for the digitisation of the strain signals. Each converter is absolutely synchronised with all other converters within the unit and across the network.
The AD2408F modules operate in a master/slave mode The first card in the system always acts as the master and as such provides the timing and synchronisation data to the rest of the systems. There are no differences in the way the master and slave cards are constructed. The master card is determined solely upon the units location within the rack.
Each of the channels are individually protected ensuring that should a sensor become short circuit then it cannot effect the operations of another channel .
The use of const current sensor excitation ensures that automatic sensor cable length compensation is carried as part of the excitation and now allowance need be made for its effect as part of any calibration or post analysis operation.
Data Synchronisation
The AD2408F contains 4 x stereo 24 bit Sigma Delta converters for the digitisation of the strain signals. Each converter is absolutely synchronised with all other converters within the unit and across the network.
The AD2408F modules operate in a master/slave mode The first card in the system always acts as the master and as such provides the timing and synchronisation data to the rest of the systems. There are no differences in the way the master and slave cards are constructed. The master card is determined solely upon the units location within the rack.
Updated : May 2010