Probe characterisation, design and evaluation for the real-time quality Indication of milk

Date
2006-12
Authors
Van der Westhuyzen, Petrus Johannes
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
In order to rapidly detect, monitor and predict changes in milk as it ferments, sensors would need to be designed specifically for milk. To this end, invasive surgical stainless steel probes were investigated and the probe impedances were characterised according to measurements made in various saline concentrations. Based on these findings, specific probes were designed that were robust and easy to use in milk. To measure multiple probe sensors continuously and accurately, an automatic measurement device was designed and manufactured. The device was self-sustaining, portable and calculated and stored all probe impedance data internally, allowing experimental runs to take place in controlled laboratory environments. The probes designed in this thesis were consequently tested in various milk fermentation experiments and it was found that surgical stainless steel probes were effective at detecting and monitoring fermentation changes. The probe impedance changes also lead the pH changes in milk, giving it a predictive element. The probe sensor studies provided enough data so that studies could be done into potential non-invasive sensors. Therefore, capacitive sensors were investigated and a fringe field capacitor was presented as a potential non-invasive milk fermentation sensor.
Description
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006.
Keywords
Detectors, Capacitance meters -- Design and construction, Electronic instruments -- Design and construction, Dissertations -- Electronic engineering, Theses -- Electronic engineering
Citation