Abstract: A network of remote sensing node assemblies, a first and second of which each has a sensor element, as well as associated technique and program code for transmitting information collected about a liquid environment. The network provides the capability of sensing the liquid to collect a wide variety of types of information/data about the liquid and any surrounding environments, and transmitting from the originating node assembly to a different node within acoustic transmission range, and then transmitting further to a third node assembly where the information may be processed and communicated to a user, or further transmitted by way of suitable medium, preferably as electromagnetic signals, to a host location for processing into a compilation of data. Each of at least two sensing node assemblies has at least one sensor element adapted for operation while immersed within the liquid, a source of power, and a transducer for receiving acoustic waves/signals transmitted from another node assembly.

Abstract: A sensing and displaying system is provided including a sensor unit having a transducer disposed in intimate contact with a vessel. The transducer senses a characteristic within the vessel like pressure and outputs electrical signal representative thereof. The sensor unit further includes a response signal generator which transmit a signal representative of the characteristic. A receiver unit receives the transmitted signal and converts it to visual indicia of the characteristic, for example, a number on a liquid crystal display. The system is capable of two-way communication between the sensor unit and the receiver unit. Both the sensor unit and receiver unit store transmitted data in internal memory.

Abstract: There is a method and disclosed apparatus for detecting for the presence within a gaseous atmosphere of a gas of a concentration above a preset level. The detecting apparatus comprises a sensor including a heater/anode element and a collector/cathode element disposed to define a space therebetween through which the gaseous atmosphere flows. An actuable power supply is coupled to the heater/anode element and to the collector/cathode element for applying power thereto, whereby ionization of the gas causes a current flow through the collector/cathode element of a magnitude proportional to the concentration level of the gas in the gaseous atmosphere. An actuable alarm means provides an indication of the presence of the gas above the preset level. Detecting apparatus control operates the detecting apparatus in a monitoring mode, wherein the power supply is actuated and the alarm deactuated to detect and compare the current flow with the preset level.

Abstract: There is disclosed a method and apparatus for repetitively taking samples of a predetermined quantity of a test gas in a liquid and introducing these samples to a test chamber. Each sample is agitated to release therefrom the test gas. The released gas is then conveyed to a sensor, which monitors the released gas for the presence of a concentration above the threshold level to produce an alarm indicative thereof. The samples of the test gas in a liquid may be repetitively taken from one zone of a plurality at a time until each zone is sampled. After one sample has been tested in the test chamber, it is discharged therefrom and the test chamber is flushed with a sample of the liquid and test gas taken from the next zone of the plurality before introducing the next sample from the same, next zone.

Abstract: A method for discovering amounts of halogen in a liquid is provided wherein the a reservoir comprising the liquid and suspected halogen is healed to a temperature characteristic of the solubility of halogen in the liquid to provide a vapor. After condensing, a sampling vapor is provided to from which the amount of halogen may be detected.

Abstract: Two embodiments of a molten metal gauging and control system using a fixed position capacitance sensor and methods therefor are disclosed. The first embodiment discloses a molten metal gauging system, the output of which can be used by various different external control systems to adjust the flow of molten metal appropriately. The second embodiment discloses a molten metal gauging and control system that comprises the molten metal gauging system of the first embodiment in conjunction with a tapered pin positioner system as the element to control the flow of molten metal.

Abstract: An improved oscillator circuit and method for measuring capacitance and small changes in capacitance is described. The circuit provides a digital output signal that has a frequency inversely proportional to the capacitance being measured, is substantially immune to stray capacitance, has low sensitivity to noise and temperature variations, is relatively simple and inexpensive to implement and provides a high precision measurement. One embodiment of the oscillator includes a capacitor to be measured, an integrator, an inverting amplifier, a comparator, a summing amplifier and a digital output circuit. A second embodiment of the oscillator further provides compensation for the non-linear response of a parallel plate capacitive transducer.

Abstract: An improved oscillator circuit and method for measuring capacitance and small changes in capacitance is described. The circuit provides a digital output signal that has a frequency inversely proportional to the capacitance being measured, is substantially immune to stray capacitance, has low sensitivity to noise and temperature variations, is relatively simple and inexpensive to implement and provides a high precision measurement. One embodiment of the oscillator includes a capacitor to be measured, an integrator, a comparator, a resistive attenuator, a summing amplifier and a digital output circuit. A second embodiment of the oscillator further provides compensation for the non-linear response of a parallel plate capacitive transducer.

Abstract: A method for discovering amounts of halogen in a liquid is provided wherein a reservoir comprising the liquid and suspected halogen is heated to a temperature characteristic of the solubility of halogen in the liquid to provide a vapor. After condensing, a sampling vapor is provided from which the amount of halogen may be detected.

Abstract: An apparatus for monitoring the concentration levels of halogen gas in a gaseous atmosphere as confined in an enclosure over a relatively extended period of time. Such monitoring apparatus includes a sensor including first and second electrodes disposed to define a space therebetween through which the gaseous atmosphere flows and a voltage source for applying a voltage between the first and second electrodes whereby an ionization current flows to the first electrode. A control mechanism illustratively in the form of a programmed microcontroller monitors the ionization current collected by the first electrode as the output signal of the sensor, to determine an increase therein as would be indicative of a halogen leak. Upon determining an increase of the sensor output signal above a predetermined difference, the control mechanism removes the energization from the halogen sensor whereby the ionization current is terminated and the life of the sensor extended.