Test & measurement


is extensively used as a safety feature integrated into vehicles. This is an optical measurement technique which helps to map environments, identify obstacles and assist with vehicle navigation.


The technology works by measuring the time it takes for light pulses to travel to an object and return to the sensor. This is particularly important for vehicle safety systems, as it helps create accurate 3D maps of the surroundings to avoid potential collisions. Additionally, optical sensors are used in automotive manufacturing to check for defects in parts, ensuring the integrity of components such as headlights, sensors, body panels. Light-based measurement systems also aid in testing the performance of air conditioning systems, inspecting exhaust emissions, and monitoring fuel efficiency, as well as detecting harmful gases. In both water quality and food safety, optical metrology systems are essential tools for detecting contaminants and ensuring that products meet regulatory standards. Water quality testing, for example, involves measuring the concentrations of various chemicals, such as dissolved gases, salts and microorganisms. Methods vary but dissolved organic molecules commonly exhibit strong absorption in the ultraviolet


(UV) range. This method determines organic pollutants present in industrial drainage and river water by measuring the pollutants’ absorbance of UV light. One approach to nitrogen measurement is converting dissolved nitrogen into nitrates. UV absorption spectroscopy (commonly at 220 nm) is a powerful technique for measuring these nitrates. The challenge lies in developing sensors that can work in complex environments where the matrix of materials may interfere with measurements. Real-time measurements must be highly accurate and provide immediate feedback to control systems, ensuring that water purification processes run efficiently. In food production, optical technologies such as UV-Vis and near-infrared (NIR) spectroscopy are


used to check food quality, looking for pesticides, contaminants, and spoilage.


By analysing the light reflected or transmitted through the product, these sensors can assess its quality in a non-destructive manner. For example, NIR spectroscopy is commonly used in the agricultural industry for determining the moisture content, protein level, and fat content of foodstuffs like grains, meat, and dairy products. However, the challenge of integrating these techniques into fast-paced production lines is significant. Calibration, variability in sample properties, and the need for highly sensitive, robust systems all pose hurdles to deploying such systems on a large scale. Recent advances in quantum imaging and optical metrology are paving the way for even more accurate


Continued on page 36... Instrumentation Monthly April 2025 35


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80