Detector pulse forming system for nuclear well logging tools
AssigneeHalliburton Company
InventorsAllen Nunley, John G. Kampfer
Life of this patent
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Abstract
For use in a nuclear well logging tool, detector pulse simulator circuits in the preferred and illustrated embodiments are set forth. The simulator circuit is adapted to be placed in a sonde for connection with a well logging tool to provide simulated detector pulses. It is selectively switched on to the output a calibrated pulse sequence function through a number of different levels. It incorporates a circuit means forming pulses limited in amplitude by an envelope yielding pulses of differing amplitude in progression. The circuit is stepped repetitively through its range of operation, for example, from a minimum voltage peak to some specified maximum and then recycles.
Claims4
A pulse simulator for generating output pulses of controlled amplitude and frequency for use in a downhole nuclear well logging instrument for calibrating a pulse height analyzer for measuring the energy of radiation from materials in the vicinity of a well borehole, comprising:
- means for generating a plurality of voltage pulses of approximately constant amplitude at a repetition rate controlled by a clock oscillator;
- digital means responsive to said clock oscillator for generating a digital control signal for determining the amplitude of said output pulses of said simulator;
- and
- means responsive to said approximately constant amplitude pulses and said digital control signal for generating therefrom a plurality of analog voltage pulses having monotonically increasing or decreasing amplitudes as a function of time.
Dependencies are inferred from the claim text.