The implementation of a fast fluorescence life‐time imaging method in a confocal laser scanning microscope is described. The set up utilizes a low‐power continuous wave (CW) argon ion laser equipped with an electro‐optic chopper producing nanosecond pulses with a repetition rate up to 25 MHz. A time‐gated detection technique enables the measurement of the lifetime of a pixel in 40 μs. The first confocal fluorescence lifetime contrast images are presented. Application of fluorescence lifetime imaging in multilabelling experiments for discrimination between different labels with overlapping emission bands, for probing the local environment of a fluorescent molecule, and for quantitative fluorescence are discussed.

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For developing a system capable of on-line detecting and localizing PDs in MV power cables, the choice of the sensor type is crucial. Sensors for detecting PDs can be divided into two main groups: capacitive and inductive sensors. In this paper, the advantages and disadvantages of these two types of sensors are discussed for on-line application. In multi-conductor cables, e.g. a three-phase belted cable, it is essential to distinguish the different propagation channels. When the cable is under normal operating conditions, all three the phases are energized simultaneously, implying that the PD pulses are propagating through two distinctive propagation channels: the Phase-to-Phase (PP) channel and the Shield-to-Phase (SP) channel. Measuring sensors can therefore also be subdivided with respect to the detected channel. If sensors can detect signals in all three conductors separately, both SP and PP channels are obtained. In this paper different positions in a substation for placing sensors are evaluated, with respect to the measured propagation channels, signaland interference sensitivity, safety and practical applicability.