Vibrating
Wire Strain Gauges
AquaLOG
VibWire-108
AquaLOG
AquaDAT
SDI-12
Network
Geotechnical
Instrumentation
Strain
Gauge Applications
Along
with standard strain gauges and load cells the AquaLOG range
of instruments can also be used to read strain from vibrating
wire strain gauges when deployed with the VibWire-108
interface unit as shown connected below.
R4
R1
R2
R3
VX
Excit
Gnd
Gnd
Excit
A
B
C
D
R4
R1
R2
R3
VA
VX
Gnd
Excit
A
B
VX
Rf
Rs
VB
Excit
Gnd
A
B
Gnd
C
D
Excit
4
Wire Half Bridge
Excit
A
3
Wire Half Bridge
Vx
VA
VB
Rf
Rs
6
Wire Full Bridge
The
AquaLOG range of instrumentation can be deployed to use nearly any
strain gauge or load cell including vibrating wire gauges
available from many different manufacturers. Each instrument
has 8 differential and/or 16 single ended inputs with user defined
sensor excitation enabling ¼,
½ bridges as
well as support full 4 and 6 wire bridges.
Strain gauges can be fitted onto any channel but when noise
immunity is essential then connection to the differential inputs is
essential. When low cost large channel count solutions are required
then block excitation and use of the single ended inputs may be the
preferred choice.
The AquaDAT analogue sensor interface is connected on to a data recorder via the SDI-12
network enabling many channels to be used by simply adding new units
when required. The AquaLOG supports up to 200 separate channels using
the AquaDAT sensor expansion into a single device.
The AquaDAT analogue sensor interface is connected on to a data recorder via the SDI-
The
VibWire-108 range of instruments support most manufacturers
vibrating wire strain gauges.
When operating with the AquaLOG data logger no user configuration settings are needed to be defined to sensor operating characteristics simply install and take readings
When operating with the AquaLOG data logger no user configuration settings are needed to be defined to sensor operating characteristics simply install and take readings
400
- 6 KHZ Range
USB
Flash Card Interface
The
circuits below demonstrate how the different gauge configurations are
connected to the instrumentation. A simple pull down menu system is all
that is needed to configure the different bridges for operation within
the AquaDAT.
Noise
Immunity
Each sensor input attached to the AquaDAT can be set to provide an average measurement reading over a set time period. This time period can be assigned to remove the effects of 50 and 60 Hz mains supply electromagnetic interference, or any other period when used to remove mechanical noise in a measurement.
Each sensor input attached to the AquaDAT can be set to provide an average measurement reading over a set time period. This time period can be assigned to remove the effects of 50 and 60 Hz mains supply electromagnetic interference, or any other period when used to remove mechanical noise in a measurement.
Measurement
Operations
The AquaDAT interface provides true bipolar measurements to remove offset errors and powers off any sensor excitation between measurements in order to eliminate self heating effects of the gauges. All the analogue inputs are auto-ranging
to ensure the highest resolution and lowest noise on a measurement.
The AquaDAT interface provides true bipolar measurements to remove offset errors and powers off any sensor excitation between measurements in order to eliminate self heating effects of the gauges. All the analogue inputs are auto-
Vibrating
Wire Strain Gauge
ZigBee
Modem
SDI-12
Network