The Applied Physics Systems Model 751 gamma sensor measures background gamma radiation in order to detect the presence of porous petroleum reservoirs (sands and limestones) occurring in well bores, which are generally less radioactive than nonporous strata (shales).
Read Morehe Model 751 can be used either as a standalone system or with the Model 760 or Model 760 Directional Sensors. Communication with the Model 751 is accomplished using a bidirectional TTL serial port. To achieve high gamma sensitivity, a scintillation crystal is used to detect gamma rays.
The sensors are calibrated to the American Petroleum Index (API) and temperature calibrated to ensure that it is accurate throughout the range.
The Model 751 also has a two-axis 50 gee vibration sensor to monitor drilling induced vibration and shock. The vibration sensor is oriented to measure axial and lateral shock and vibration.
Two communication protocols are available over a bidirectional serial data link to the surface: ASCII and binary at up to 9600 baud. An ASCII data stream can be easily displayed with a terminal program while binary is used for high speed sensor to host interchange.