Multiple-Channel Conductometer for Measuring Salinity Concentrations in Laboratory Flows,

摘要

A multiple-channel conductometer for measuring salinity concentrations in laboratory flows is described. Channel-to-channel influence and sensitivity to extraneous grounds have been reduced to acceptable levels by a unique probe excitation and detection system which keeps the fluid at ground potential. Conductivity rather than resistivity is measured to eliminate nonlinear concentration-voltage relationships,and special circuits are included to make calibration curves independent of the cable length between probe and instrument. The system has been designed with outputs suitable for analog and/or digital processing and with emphasis on ease of operation and reliability. The electronic system utilizes operational-amplifier technology jointly with discrete components to optimize signal processing and to take advantage of recent advances in the electronic industry.