Abstract: A hazardous fluid materials transfer system is automated to control the transfer of the hazardous fluid while maintaining the fluid within a closed environment for providing maximum personal protection to the operators handling the hazardous materials during the transfer, such as those operations in the mosquito control industry. The system includes the transfer of the fluid to storage tanks intermediate the source and target tanks between the transfer is desired. A pre-programmed processor receiving pressure, weights, and connection signals from transducers, such as pressure sensors and load cells, located throughout the system controls the operation of pumps and valves to allow the fluid being transferred to remain within a closed environment.

Abstract: A hazardous fluid materials transfer system is automated to control the transfer of the hazardous fluid while maintaining the fluid within a closed environment for providing maximum personal protection to the operators handling the hazardous materials during the transfer, such as those operations in the mosquito control industry. The system includes the transfer of the fluid to storage tanks intermediate the source and target tanks between the transfer is desired. A pre-programmed processor receiving pressure, weights, and connection signals from transducers, such as pressure sensors and load cells, located throughout the system controls the operation of pumps and valves to allow the fluid being transferred to remain within a closed environment.

Abstract: A hazardous fluid materials transfer system is automated to control the transfer of the hazardous fluid while maintaining the fluid within a closed environment for providing maximum personal protection to the operators handling the hazardous materials during the transfer, such as those operations in the mosquito control industry. The system includes the transfer of the fluid to storage tanks intermediate the source and target tanks between the transfer is desired. A pre-programmed processor receiving pressure, weights, and connection signals from transducers, such as pressure sensors and load cells, located throughout the system controls the operation of pumps and valves to allow the fluid being transferred to remain within a closed environment.

Abstract: A device for in situ cleaning a fouled membrane of a sensor disposed in an aqueous process solution includes a first electrolysis electrode disposed in the process solution immediately adjacent the membrane, a second electrolysis electrode disposed in the process solution and spaced apart from the first electrolysis electrode, and a controllable power source for passing a current between said first and second electrodes. The current produces a heavy concentration of ions at a surface of the fouled membrane. The polarity of the current is selectable to produce negative or positive ions for reacting to decompose deposited salts, or to scrub contaminates from the membrane surface.

Abstract: A dissolved oxygen measurement system includes real time monitoring and calibrating of a dissolved oxygen sensor. The sensor includes a pair of measuring electrodes, an electrolyte, and a pair of closely spaced electrolysis electrodes. The housing includes a permeable membrane and is immersed in the process solution. A computer is provided, programmed to perform dissolved oxygen concentration measurement, and continuous monitoring of the membrane impedance and sensor condition. A test electrode is disposed in the process solution adjacent the membrane and is driven by a low level pseudorandom binary signal from the computer producing a current through the membrane impedance which is monitored by the computer. Small pulses of direct current are passed between the electrolysis electrodes, producing small increases in oxygen.

Abstract: A device for use in a system for providing on-line, real-time monitoring of the condition of a sensor immersed in a process solution, the sensor having a membrane, by periodically generating known changes in characteristics of the process solution adjacent the membrane, the device providing a fixed volume of the process solution adjacent the membrane, the fixed volume being independent of a flow rate of the process solution. The device include a shield of non-conductive material, and having a retracted position permitting flow of the process solution past membrane, and an extended position enclosing the membrane to provide a fixed, stationary volume of process solution adjacent said membrane. The shield is selectively moved from its retracted position to its extended position during monitoring of the condition of the sensor.

Abstract: In a real time, on-line pH measurement of an aqueous solution, a system provides continuous data on the physical condition of the pH sensor. The system includes a pH sensor having a membrane disposed in the process solution with a first external electrode attached to outer surface of the membrane and a second external electrode adjacent the sensor. The two electrodes in the solution are periodically driven by a short time duration dc signal producing a direct current between the two electrodes. The direction of the current through the solution is periodically reversed. This action results in electrolysis of the H.sub.2 O molecules of the solution between the two electrodes producing controlled changes in hydrogen ion concentration at the sensor. One current direction produces an increase in pH and the other direction produces a decrease in pH.

Abstract: In a real time, on-line pH measurement of a process solution, a system provides a continuous data of the physical condition of the pH sensor. The system includes a pH sensor having a glass membrane disposed in the process solution and two electrodes in the solution adjacent the sensor. The two electrodes in the solution are periodically driven by a short time duration dc signal producing a dc current between the two electrodes. This action results in electrolysis ofo the H.sub.2 O molecules of the solution at the two electrodes and a resulting decrease in hydrogen ion concentration (a rise in pH value) in the region of the sensor. The sensor response to the increase in pH in the solution is a direct indicator of the complete sensor and system performance and is monitored and analyzed. Visual readouts and threshold alarm circuits are provided which indicate changes in the sensor response to the pH change indicative of a sensor or system degradation or fault.

Abstract: A system for real time, on-line dissolved oxygen (DO) measurement of a process solution provides continuous data of the physical condition of the DO sensor and of the entire system performance. A DO sensor is disposed in the solution with two external electrodes adjacent thereto. A time-varying low level signal is applied to one electrode producing a current through the sensor membrane and grounded electrode, which is detected by a cross-correlation circuit to monitor the membrane impedance. The other electrode is periodically driven by a short, low level dc pulse, producing electrolysis of the water between the two electrodes, and generating a small, repeatable amount of oxygen ions. The sensor response is analyzed providing a direct indication of the sensor and system performance.

Abstract: A real time, on-line ion mesurement system for a solution has continuous monitoring of the physical conditions of the ion electrode and the reference electrode of the system. A dual chamber reference electrode is provided having an inner chamber and electrode for providing an ion measurement reference potential, and an outer chamber and electrode for producing a monitoring potential to detect poisoning of the reference electrode membrane. A first time varying low level signal is applied to the ion electrode and a second time varying low level signal orthogonal to and uncorrelated with the first signal is applied to a solution ground electrode disposed in the solution adjacent the reference electrode, the signals producing a composite common ground current. A pair of cross-correlators extracts the two time varying components from the common ground current for measuring the ion electrode and reference electrode impedances.