Thermal-Imaging Method for Monitoring the Insulation Condition of Oil-Filled Equipment

The method of thermal imaging inspection allowing detecting defects at an early stage of their development is considered. The essence of the method consists in recalculation of measured temperature drops into insulating characteristics measured under operating voltage. It is shown that defects are detected at the early stage of their development using the defect detection criterion (tgδmeas-tgδcalc). It is concluded that it is possible to abandon a number of traditional methods of testing with electrical equipment shutdown.

Crack Detection Zones: Computation and Validation

During the development of aerospace structures, typically many fatigue tests are conducted. During these tests, much effort is put into inspections in order to detect the onset of failure before complete failure. Strain sensor data may be used to reduce inspection effort. For this, a sufficient number of sensors need to be positioned appropriately to collect the relevant data. In order to minimize cost and effort associated with sensor positioning, the method proposed here aims at minimizing the number of necessary strain sensors while positioning them such that fatigue-induced damage can still be detected before complete failure. A suitable detection criterion is established as the relative change of strain amplitudes under cyclic loading. Then, the space of all possible crack lengths is explored. The regions where the detection criterion is satisfied before complete failure occurs are assembled into so-called detection zones. One sensor in this zone is sufficient to detect criticality. The applicability of the approach is demonstrated on a representative airplane structure that resembles a lower wing section. The method shows that four fatigue critical spots can be monitored using only one strain sensor in a non-intuitive position. Furthermore, we discuss two different strain measures for crack detection. The results of this paper can be used for reliable structural health monitoring using a minimum number of sensors.

Japanese Food Allergen Labeling Regulation: An Update

The Japanese food allergen labeling regulation was designed to match real Japanese food allergy circumstances and also to be enforced effectively; thus, (1) regulated food allergens were selected by prevalence and seriousness according to food allergy surveys in Japan; (2) the detection criterion for ELISA monitoring, 10 μg food allergen protein/g (or mL) food, was set up as the threshold value to regulate commercial prepackaged foods; and (3) official food allergen analytical methods, which can determine the threshold value accurately, were developed. These three points are distinctive from other countries. Furthermore, as an on-going project, the regulation has been amended according to food allergy circumstances and requirements of society. This paper presents recent changes regarding the Japanese food allergen labeling regulation. To date, the Japanese food allergen labeling regulation has been enforced for more than 15 years and seems to be working effectively. Now would be an opportune time to review the regulation for its next level of development.