Abstract: A self-contained, down hole powered electrical system in which a well tool microprocessor and circuitry can be programmed from an external microprocessor and verified as to functional capabilities and data can be retrieved from the tool by use of a current and voltage encoded binary system. Further, the system includes an alarm system for verifying the operation of the tool.

Abstract: A self-contained, down hole powered electrical system in which the tool has nonvolatile memory means which are independent of applied power thereby permitting the power to the system to be turned off between sampling and further including a system for reentering data to nonvolatile memories for retention during high temperature operations.

Abstract: A self-contained, down hole powered electrical system in which the available power of a battery source is matched by a power conversion means to the power required in the down hole equipment and the power conversion means provides a regulated voltage output.

Abstract: A coulometric titrator for determining, at high accuracy and without time delay problems, small amounts of a specific (chloride) ion in a solution by the addition of a reactive ion. A sensor provides a first voltage representing the logarithm of the specific ion concentration to a differential amplifier which also receives as an input a signal from a reference electrode. The differential amplifier produces an error signal applied to a comparator and referenced therein to a certain reference voltage representing a desirable range of rates of change of the error output voltage. The comparator provides a sensor signal voltage representing the difference between the error signal and reference voltage. This sensor signal voltage is applied to an antilogarithm converter which produces an output signal that is proportional to the antilogarithm of the sensor signal voltage.

Abstract: An improvement to an automatic correcting type of corrosion ratemeter (e.g., U.S. Pat. No. 3,717,566) with test specimen, reference and third electrodes in contact with corrodant and "null" and "measurement" circuitry whereby correcting is made for freely corroding potential and addition of reference polarization potential between the test and reference electrodes in conjunction with controlled current flow between the test and third electrodes. The improvement comprises unique circuitry for common base, steady state readouts eliminating asynchronous cycle time problems and providing precise simultaneous readout(s) calibration.

Abstract: A redundant intrinsic safety barrier with input and output terminals and circuit common connecting a plurality of signal lines. Input and output directors connect respectively to the input and output terminals. The directors are connected to each other and each of the directors provides dual unidirectional current paths from one of the input or output terminals to circuit common. Unidirectional current latching means in each current path provide a high impedance gap for voltage magnitudes below a predetermined value, and the latching means are self-latched into a low impedance bridge for current magnitudes above the predetermined value. Fused means in series with the input and output directors open the circuit therebetween when current in a certain time period exceeds the predetermined value by a certain selected amount.

Abstract: A voltage sweep generator provides a linear sweep voltage signal (triangular wave) between first and second magnitudes in the output circuit of an integrator driven by a control signal. The control signal is produced by a control network responsively to a control signal voltage of fixed magnitude but positive or negative in polarity. The linear sweep voltage signal correlates to reference voltages in a comparator with resultant limits switching signals. These switching signals activate a bistable amplifier to produce the control signal voltage of fixed magnitude and a polarity determinative of ramping up or down voltagewise.The voltage sweep generator is especially useful in a novel dynamic analyzer for evaluation of voltage-current related properties in an external system and, in a particular application, to a unique potentistat employed in performing electrochemical analysis of corrosion phenomena in a test cell.