Abstract: A method, for measuring the parameters of cathodic protection of the structures which are protected by electrolysis or by sacrificial anodes, comprises fixed programs for executing data acquisition and processing, measurement steps with high speed data sampling and digitizing in the passive and active modes of operation, generating a constant current pulse being sourced into or sunk from electrolyte containing said structures while in a measurement step, and generating a forced off-state condition in the vicinity of a test point of said structures. And, an active corrosion analyzer, (for implementing said method for measuring the polarized potential, the IR-drop, the depletion region capacitance, the coating capacitance, the equivalent voltage, and the equivalent resistance), comprises a microcontroller, a precision timing generator, a non-volatile memory, a random access memory, an analog to digital converter, constant current generators, and control elements.

Abstract: An environmental measuring and recording apparatus includes a pressure transducer for measuring of pressure conditions in an oil reservoir. A temperature transducer is used to measure the temperature to which the pressure transducer is subject. The measured temperature is used to compensate the pressure transducer and a resulting compensated signal is digitized and stored in a memory unit. Because of the extreme environmental conditions in which the electronic apparatus is operating the memory unit has the capabilities of periodically being refreshed and to retain data after the removal of power.

Abstract: A compensating transducer digitizer circuit provides for compensating the digital output of a measuring transducer with the digital output of a compensating transducer through the interaction of the quasi-digital outputs of the compensating transducer and measuring transducer without altering their quasi-digital outputs compensating transducer.

Abstract: A bourdon tube transducer has included a bourdon tube with a conductive plate electrically separated from the bourdon tube and in parallel with the bourdon tube. As the pressure varies, so does the electrical reactance between the bourdon tube and the conductive plate and this variation is used to vary the frequency of an electrical oscillator that is connected to the bourdon tube and the conductive plate.

Abstract: Apparatus for measuring and recording environmental conditions in a deep bore hole using a down hole gauge including pressure and temperature sensors and data processing elements is disclosed. A pressure transducer such as a Bourdon tube is provided for measuring the down hole pressure. An encoder coupled to the pressure transducer produces a plurality of data bits defining a coded word representative of the down hole pressure. A temperature transducer is also provided for measuring the down hole temperature. An oscillator is coupled to the temperature transducer for providing a timing signal having a frequency which is proportional to the down hole temperature. Serial shift registers are provided for recording data bits in separate groups of bits defining data words which are representative of the down hole pressure and temperature conditions.

Abstract: A method and an apparatus for connecting a gage to an oil well pump power cable for transmitting pressure and temperature data to a surface recorder whereby the gage can be selectively disconnected when it is desired to test the insulation integrity of the pump power supply system, and selectively connected when the test is completed. The gage is connected to the neutral point of the three phase motor winding through a latching relay. A code transmitter generates a frequency coded signal on the power cable to a decoder which controls the relay. The same coded signal is utilized to open and close the relay contacts as desired.

Abstract: a Bourdon tube is situated down hole in an oil well or the like, and has attached thereto a coded wheel which rotates an amount determined by the sensed down hole pressure. The wheel has a number of transparent and opaque concentric bands thereon which form a gray code pattern indicative of a selected range of pressures. A plurality of radiant energy transmitters are radially positioned on one side of the wheel in optical alignment with each of the respective bands. A plurality of radiant energy sensors are positioned and aligned in a like manner on the other side of the wheel for sensing the passing or blocking of the radiant energy by the respective bands formed on the wheel. Included is a digital logic circuit controlled by a temperature responsive oscillator which provides timing signals having a frequency determined by the sensed down hole temperature.

Abstract: A Bourdon tube is situated down hole in an oil well or the like, and has attached thereto a coded wheel which rotates an amount determined by the sensed down hole pressure. The wheel has a number of transparent and opaque concentric bands thereon which form a gray code pattern indicative of a selected range of pressures. A plurality of radiant energy transmitters are radially positioned on one side of the wheel in optical alignment with each of the respective bands. A plurality of radiant energy sensors are positioned and aligned in a like manner on the other side of the wheel for sensing the passing or blocking of the radiant energy by the respective bands formed on the wheel. Included is a digital logic circuit controlled by a temperature responsive oscillator which provides timing signals having a frequency determined by the sensed down hole temperature.