Alistair Chambers, winner of the Level 7 Category at last year’s Innovative Student Engineer of the Year Awards, outlines the development behind his winning device, a digital in-cab bale moisture meter that allows straw moisture and quality to be easily and efficiently assessed at all stages


Alistair Chambers was the Level 7 Category winner at last year’s Innovative Student Engineer of the Year Awards. His winning device, a ‘Digital in-cab bale moisture meter’, allows straw moisture and quality to be easily and efficiently assessed at all stages, from the field to the end-user. With the capacity to be retrofitted to any tractor-mounted or loader-mounted bale handler with removable tines, the device is a simple and cost-effective way of ensuring a quality product for sale in livestock and equine markets or new emerging markets in green energy.

The idea for the award-winning project came to me in September 2013 during the final days of the harvest, in the usual rush to get all of the the straw from the field to the shed. Late one evening, while sitting in a tractor moving bales, I wondered if it was possible to read the moisture of the bale without having to get out of the tractor. Whether this stemmed from laziness or a drive for efficiency, I’m still not sure!

A couple of weeks later, the project supervisor in Carlow Institute of Technology (where I was and still am studying for a degree in mechanical engineering) mentioned the Innovative Student Engineers of the Year Awards. When he spoke about the Awards to the third-year group, asking what project we would be attempting, I mentioned the idea of a bale tine moisture meter. After some head scratching, it was decided that it was a worthwhile project.

Then the fun started. Firstly, the physical piece of the project was designed using SolidWorks, a 3D mechanical computer-aided design program. This proved to be more complicated than expected, however – the wires to the probe needed to be routed through the centre of the tine to the probe near the tip, without affecting the structural integrity of the whole tine and its ability to carry the physical loads required.

Once this was completed, the electrical and wiring design was started. Being a mechanical engineering student, I had little or no experience in the this area. However, after a lot of googling and discussions with the electronics department, it was decided that using a voltage divider circuit linked to a micro controller was the best route to go down. This would read the resistance of the straw and then, from that, calculate the moisture content.

An Arduino micro controller was subsequently sourced and a basic understanding of the programming language for Arduino was gained. From here, a program to convert the raw data coming back from the probe in the tine was built and tested with known resistances.

The physical tine was manufactured using a computer-numerical controlled lathe in IT Carlow. This was also a steep learning curve for me, as I had no skills in this area prior to this project.


Once the physical part of the device was manufactured, the assembly process began. This process started shortly after Christmas 2013 and threw up some interesting challenges along the way. One of these was ‘chasing’ the wires along the length of the tine without damaging them – if the insulation was damaged, it would affect the resistance reading and thus the moisture reading of the probe. Once this obstacle was cleared and the assembly was complete, it was connected to the controller and testing of the device could begin.

Firstly, bench testing was carried out using a currently owned handheld moisture meter for comparison purposes. The results were shown to be comparative, which was good news. From this point, it was decided that full testing should commence. So, the tine was fitted to a loader on my home farm, the microcontroller was mounted in the cab of the tractor and the product was tested both for accuracy in comparison with the commercially available unit and also for structural integrity under the load exerted in normal use.

All of the above on farm tests were video recorded for my final presentation in Carlow Institute of Technology (this proved very useful when I eventually ended up in 22 Clyde Road some months later). In the meantme, a detailed report on the project was subsequently compiled and handed up for marking. A short time later, in discussions with the project supervisors, it was decided that I should enter the Innovative Student Engineer of the Year Awards with this project.

The application process was quite simple – all of the information that was required to fill in the application form and compile a summary of the project was already in the detailed report I had handed into IT Carlow a few weeks previously. These were sent off to Engineers Ireland and then the waiting began to see if I had made the short list.

The phone call did indeed come. During the call, I was told that my presence was required in the Engineers Ireland headquarters on Clyde Road at a given date and time, to give a 15-minute presentation on my project to a panel of highly qualified and respected engineers from the event sponsors Siemens and Engineers Ireland.

The panel members were also to spend five minutes questioning me after the presentation, which was a scary prospect! I decided that preparation would be key to getting through it. I put together a PowerPoint presentation on the project and practised it a few times in front of friends and family – none of whom had any idea what I was talking about. However, this strategy proved invaluable on the day.


On the morning of the presentation, I drove to Dublin. A couple of lecturers from IT Carlow and my parents came along too, for moral support. It was a great day and it was also very interesting to see and hear what other students were doing around the country. My presentation went off without any hitch and the questions were answerable. Then came the moment of truth, when the results were announced. I still cannot believe that my name was called out as winner of the Level 7 Category, as the standard of the projects I was up against was very high.

It was a very enjoyable day and I would advise anyone who has the opportunity to enter his or her project in the competition to do so.

Since winning this award, I have had interest in my device and hope to develop it further once I have completed my final year in IT Carlow. I believe that once I qualify, having won this award will be worth its weight in gold when I am applying for jobs, as it will make my CV stand out from other applicants.

The aim of the Innovative Student Engineer of the Year Awards is to highlight excellence in engineering degrees across Ireland. The competition is judged on merit of final-year projects. Final-year students of Level 7 and Level 8 engineering degree programmes accredited by Engineers Ireland are eligible to enter. The final of this year’s competition will take place on Friday, 6 June. Click here for more details. O'RiordanMech3D,agriculture,awards,education,Engineers Ireland,IT Carlow
  Alistair Chambers was the Level 7 Category winner at last year’s Innovative Student Engineer of the Year Awards. His winning device, a 'Digital in-cab bale moisture meter’, allows straw moisture and quality to be easily and efficiently assessed at all stages, from the field to the end-user. With the capacity to...