Abstract: A system for real-time sizing of fluid-borne particles is disclosed. The system further determines, in real time, whether the detected particles are biological or non-biological. As the fluid is being tested, it is exposed to a microbe collection filter which is cultured to determine the type of microbes present in the fluid being tested.

Abstract: A particle detection and classification system is disclosed. The system determines the size of measured particles by measuring light scattered by the particles. The system simultaneously determines whether measured particles are biological or non-biological by measuring fluorescent light from the particles. The system uses a parabolic reflector, and optionally, a spherical reflector to collect fluorescence light.

Abstract: A system for real-time sizing of fluid-borne particles is disclosed. The system further determines, in real time, whether the detected particles are biological or non-biological. As the fluid is being tested, it is exposed to a microbe collection filter which is cultured to determine the type of microbes present in the fluid being tested.

Abstract: A short-circuit protected switched output circuit having: an input node (I10) for receiving an input switching signal; an output node (O10) for outputting a switched output signal; switch means (Q10) connected between the input and output nodes; and a Schmitt trigger NAND gate oscillator arrangement (C10, D11, D12, NG10, R12, R13, R14) having an input coupled to the output node and having an output coupled via diode means to the input node, whereby the oscillator arrangement produces a low frequency, low duty-cycle, fixed-frequency signal at the output node in the event of the output node being short-circuited. An alternative circuit using a Schmitt trigger inverter are also disclosed.