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.
These sensors connect to data loggers or radio controlled management systems
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
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
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.
PEAK ENVIRONMENTAL MONITORING
monitoring and control systems for profitable and efficient water management