Abstract: An improved detector assembly of an electro-magnetic conduction-type conductivity meter includes a plastic housing member having a liquid sample flow path extending therethrough. An excitation transformer is mounted in a cavity of the housing member along with the detection transformer for respectively inducing a current flow and detecting a current flow in the liquid sample flow path. A porous electrode is positioned adjacent one of the transformers and insulated by hydrophilic paper so that the entrance of any fluid within the cavity can be detected.

Abstract: In an improved electromagnetic induction-type conductivity meter utilizing primary and secondary transformer coils about a liquid sample passageway, a resistance circuit having a conductive lead line extending also through the coils and parallel with the sample passageway is provided. The resistance circuit can be selectively opened and closed, and has the capacity to contribute to the measurement voltage detected on the detector coil when the primary coil is excited. The value of this additional resistance voltage can be used for calibration and monitoring the condition of the conductivity meter.

Abstract: An improved detector assembly with an electromagnetic induction-type conductivity meter is provided with a pair of housing members forming a first liquid sample flow path at a central location, and a second liquid sample flow path on their outer circumference. An excitation coil and a detection coil extend about the first liquid sample path, while the second liquid sample flow path interconnects with the first liquid sample flow path both upstream and downstream of the respective coils. The second liquid sample flow path can substantially extend about the coils so that a relatively large induction current can be generated and measured as representative of the liquid sample.

Abstract: An improved apparatus for measuring fine particles in a liquid includes a nozzle for spouting water from within one end of a cell towards an opposite end thereof. An incident light beam traverses the spouted water to scatter light towards a light detection system exteriorly of the cell. The detection system includes a stop for excluding scattered light from being detected and which resulted from fine particles outside a central portion of the spouted liquid.