We work mainly with two or three types of soil probes which we regard as the best
in their technology. These are the Sentek range of products from Sentek
Technologies in Adelaide ( Australia ) and EnviroPro which is a multi level soil probe
providing data on soil moisture, soil salinity and soil temperature.
In addition we have installed Aquaflex soil moisture straps in playing field and public
open space areas.
What is a capacitance probe ?
A capacitance soil probe measures the dielectric constant of a soil. From this value
a level of soil moisture can be determined using a series of soil co-efficient
algorithms.
Sentek capacitance soil sensor
The Sentek soil capacitance sensor makes up the sensing component of the Sentek
soil probe. Multiple sensors can be placed on a single probe rod allowing flexibility in
measuring depths.
What is an 'access tube' ?
an access tube is a plastic tube which is installed in the soil to allow the insertion of
the Sentek series of soil probes. The capacitance sensors don't actually come into
contact with the soil but measure soil moisture through the plastic tube.
Calibrations factors adjust for the plastic tube.
The EnviroPro soil probes do not use an 'access ' tube as the sensors are
encapsulated all as one unit. The advantage of the EnviroPro is that it can be
buried out of sight and thus ideal for open parks and public spaces.
How do you install an 'access tube' ?
- the holes for the access tubes are prepared by very careful auguring a hole a
few millimeters larger than the diameter of the access tubes. We use what is known
as the 'slurry' installation technique where we make up a soil slurry and pour this
into the augured hole. We then push the access tube into the slurry. This ensures
that there is a very tight fit of the access tune and no air gaps between to outer
surface of the access tube and surrounding soil. We also use this slurry technique
to install the EnviroPro soil probes
What is telemetry ?
Telemetry is really just sending data via radio. We have a few
options for radio and these depend on the distances
transmitted. Most license free type telemetry in Australia uses
either what is called spread spectrum radios operating in the
900 MHz range or radios operating in lower frequencies such as
151 MHz and and 433 MHz. Distances obtained depend on
surrounding environments and we generally operate in what is
called line -of-sight situations.
We can transmit data up to 16 kilometers in some situations
and then can also deploy repeater units to increase the
flexibility of the transmission.
What is GPRS and Next G telemetry ?
GPRS refers to General Packet Radio Service.
This is a data transmission service offered by mobile phone
companies. We find this an exceptional way to handle
environmental data. Field data can be sent from our field units
to (our) fixed IP address. This data can then be download from
the fixed IP ( web site ) to your PC. We have found this service
provides excellent trouble free means of remote data recording.
Water quality monitoring
We usually use fixed field instrumentation connected to field data
recorders. These data recorders are then connected to the mobile phone
network or GPRS transmitters.
What parameters can you measure ?
The main parameters we measure and water level, pH , electrical
conductivity and temperature. We also measure dissolved oxygen and
currently deploying florescence based oxygen probes with good
success.These sensors are generally attached to another water quality
instrument such as made by TPS - Brisbane - Australia . In some
instances we connect the sensors direct to our data recorder
Business
How long have you been in business ?
Our business was registered in 1996 - see list of projects to get an idea
of the work done in recent years
Where do you work ?
We work work nationally and happy to work internationally as well. see
also under the About Us and Projects headings.