Abstract: A self-contained downhole apparatus for being lowered into an oil or gas well to internally record samples of at least one environmental condition comprises three body sections linearly and releasably interconnected. One of the body sections is a selected one of a plurality of transducer housing sections. The selected transducer housing section is mechanically and electrically connected to a second body section containing microcomputer-operated signal processing circuitry. The third body section contains a power supply.

Abstract: A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and de-energizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations. Samples of the monitored environmental conditions can be taken at variable rates dependent upon software monitoring of the condition, the remaining battery life and the remaining memory capacity and in response to hardware monitored pressure changes. Each sample can be taken to a selectable resolution. A watchdog circuit monitors the microprocessor to insure that it is operating within a preselected time limit.

Abstract: A security apparatus for interfacing a computer system with a telephone circuit includes a modem and a controller interfacing between the telephone circuit and a modem of the computer system. The first-mentioned modem and the controller operate to answer incoming calls in a manner to disguise that the telephone circuit is connected to a computer system, thereby masking or hiding the computer system from unauthorized users such as "hackers.

Abstract: In an oil well instrumentation system, the downhole sensor system is controlled by a computer which is powered-on only during sampling movement. An independent circuit, continuously powered, detects significant sensor rate-of-change values whereby the computer-sampling equipment is powered-on. A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and deenergizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations.

Abstract: The power-conversing apparatus includes a plurality of independently energizable electrical circuits used in receiving electrical signals from a transducer which senses an environmental condition, in processing the electrical signals, and in storing information related to the detected environmental condition. The apparatus further includes a power control circuit for continuously providing electrical power to at least one of the electrical circuits and for independently switchably providing electrical power to selectable ones of at least two others of the separately energizable circuits.

Abstract: A physical condition in a well bore is sampled and information taken from the sample is recorded by a method of conserving electrical energy in performing such sampling and recording. The method sequentially energizes and de-energizes a plurality of different electrical circuits within the downhole apparatus with which the physical condition is detected and in which the information is recorded. The method determines when the next sample is to be taken and, depending upon how much time remains until the next sample, de-energizes the apparatus to conserve energy.

Abstract: A pressure controller includes a set point switch mechanism by which a selectable pressure to be maintained in a pressure vessel can be set. The actual pressure in the pressure vessel is detected and converted into a corresponding electrical signal by a suitable pressure transducer. Electrical signals from the set point switch mechanism and the transducer are utilized by a computer to generate control signals for controlling a volume adjustment mechanism which adjusts the effective volume of the pressure vessel and adjusts the quantity of pressurizing fluid disposed in the vessel. The volume adjustment mechanism includes a piston disposed in a cavity which is connectable with the chamber of the pressure vessel. The volume adjustment mechanism also includes a stepper motor which can be moved in precise increments to adjust the position of the piston in the cavity.

Abstract: An optical reader contained in a portable case includes elements for rotating a chart containing indicia and for moving a lens and photo-responsive member substantially parallel to the axis of rotation of the chart. These elements are controlled so that the photo-responsive element detects every one of an array of discrete informational units defined by the optical reader on the chart and for generating for each discrete informational unit a respective binary bit having one of two logic values depending upon whether the respective discrete unit is relatively light or relatively dark. The reader also includes circuit elements for detecting every eighth one of the respective binary bits to define a byte of information representing eight of the discrete informational units of the chart. The reader is controlled to commence a read of the chart from the right-hand end and to incrementally read strips of the chart progressing to the left-hand end of the chart.

Abstract: A local station and a central computer subsystem remotely located from each other are interconnected by a transmission system, such as a telephone network, so that a medium containing visual data can be read in the vicinity where the cart is made, but automatically analyzed by a computer at the central computer subsystem. The local station includes an optical reader device for reading the medium and converting the visual data contained thereon into numerical data in the form of binary electrical signals. The binary electrical signals are compressed by a hardware compressor circuit and a software compressor program so that the transmission time for transmitting the data to the central computer subsystem is reduced. Once the data is transmitted to the central computer subsystem, an analysis of the data is made after any desired modifications of the data have been made through a graphics terminal.