MyWikiBiz, Author Your Legacy — Tuesday April 30, 2024
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| | Although it took a few incarnations to get the probe working properly, many units are still working ten years later. | | Although it took a few incarnations to get the probe working properly, many units are still working ten years later. |
| − | ====C-Probe Series 2====
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| − | In 2000 an application was lodged with AUSIndustry for a research and development grant to develop a soil salinity sensor {Reference needed}. Sentek had already started work on their Triscan probe and Robinson wanted to ensure his company had something to equal it, hence the S-probe project. The new project could be used not just to build a salinity probe but also to update the design of the soil moisture probe. This coupled to a desire to save on the royalties being paid to the developer of the series 1 C-Probe, led to the development being carried out in house.
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| − | By this time ADD had closed down and some of the former staff had been taken on at Agrilink. As Adcon had commenced looking at the SDI-12 interface as an option for its future products, Agrilink decided to base the new probe on this protocol. Each sensor element would act as an SDI-12 sensor and communicate through a simple pass through board to an external SDI-12 logger. For compatibility with Adcon’s older analogue radios, a board was produced which could convert the output from 6 SDI-12 sensors to 6 analogue signals.
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| − | Sentek had not patented the EnviroSCAN, but had patented a dual frequency probe for detection of salinity. Agrilink had to be careful that their new salinity probe did not breach this patent. The $1.5m project (half from AUSIndustry and half from inside the company) failed to deliver a working product. As an indication of complexity of the relationships involved, many years later, Sentek's TriSCAN may be used as a trending tool but does not provide any measure of the actual soil salinity.
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| − | If the Salinity probe development seemed ambitious, that pales compared to development of the nutrition probe or N-Probe. A share of the AUSIndustry grant money was hived off to fund investigation of a multi-level nutrient sensor which would be able to track movement of nitrogen through the profile. Spectrometry was emerging as the new tool for investigation of nutrients and for assessing parameters such as wine grape quality and this technology was seized on for the N-Probe. Like the S-Probe, the N-Probe never made it to market.
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| − | C-Probe Series 3
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| − | One of the powerful features of Sentek's original EnviroSCAN probe was that the unit was completely configurable. Users could purchase a probe in a variety of lengths and then fit sensing elements at 10cm intervals along the column. Agrilink took the same approach with the C-Probe. Flexibility always comes at a price and in this case that was cost of production. Each probe had to be custom built to order. A column was first cut to the required length, a bus bar fitted and then sensors attached to the bus bar. The completed probe was then tested and run through a normalisation process. The variable frequency oscillator used in the sensor boards is subject to a number of variables: variation in tuning coil, variation in sensor ring dimensions, variation in thickness of the tube wall and more. The completed probe would be placed in a test tank containing air and then in one containing water. This would set the low and high frequency limits for the oscillator. To account for the variability, the normalisation process stored these high and low readings and pre-scaled all future readings between them on a scale of 0 to 100 Scaled Frequency Units. The C-Probe series 3 attempted to cut some of the manufacturing steps down by switching to a fixed design: 50cm with 5 sensors or 100cm with 10 sensors. Probes would be supplied pre-normalised and the preferred installation technique was switched from through-the-tube augering to an over-sized hole and slurry. The probe would be sealed to remove the need for regular maintenance - a bugbear of previous variations.
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| − | Design of the Series 3 probe was once again performed in house. The Series 3 was represented an evolution of the Series 2 rather than a new design. The Series 3 had probably the shortest life of any AquaSpy product, being replaced very quickly by the Series 4 probe.
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