The present invention is a pressure coupling chamber (1) developed for comparison calibrations of acoustic pressure-sensitive hydrophone (2) in the frequency range from Hz to 1 kHz. A hydrophone (2), reference receiver unit (3) and acoustic source (6) under test are acoustically coupled in the chamber through the air-filled medium inside the pressure coupling chamber (1). Acoustic sources (6) that are going to create acoustic pressure in the pressure coupling chamber (1), placed on the side walls of the chamber (1) to surround the pressure-sensitive active surface of hydrophone (2), are driven to create a hydrostatic pressure effect in the related frequency range in the chamber. Calibration of tested hydrophone (2) with comparison method is carried out by measuring the output voltages of tested hydrophone (2) and the reference receiver unit (3).

A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

A method includes attaching a sensor calibration tool to a drill string. The sensor calibration tool includes a first tool sensor configured to measure a first operational parameter. A first tool sensor measurement of the first operational parameter is received from the first tool sensor, where the drill string is disposed at least partially within a wellbore and supported by a surface rig system and the sensor calibration tool is positioned on the drill string at a surface location proximate to the surface rig system. A first rig sensor measurement of the first operational parameter is received from a first rig sensor positioned on a first surface component of the surface rig system. The first rig sensor is calibrated based on a comparison of the first tool sensor measurement with the first rig sensor measurement.

A method includes attaching a sensor calibration tool to a drill string. The sensor calibration tool includes a first tool sensor configured to measure a first operational parameter. A first tool sensor measurement of the first operational parameter is received from the first tool sensor, where the drill string is disposed at least partially within a wellbore and supported by a surface rig system and the sensor calibration tool is positioned on the drill string at a surface location proximate to the surface rig system. A first rig sensor measurement of the first operational parameter is received from a first rig sensor positioned on a first surface component of the surface rig system. The first rig sensor is calibrated based on a comparison of the first tool sensor measurement with the first rig sensor measurement.

A method for calibrating an acoustic calibration tank providing the tanks with reference hydrophones positioned along the tank. The tank is filled with a fluid at a known temperature and pressure. A calibrated reverse hydrophone is positioned in the tank, opposite one of the reference hydrophones. A known acoustic wave is created in the tank using the calibrated reverse hydrophone and the opposite reference hydrophone output is measured. Free field voltage sensitivity is computed for the reference hydrophone. This gives the calibration factor for the reference hydrophone. The calibrated reverse hydrophone can be repositioned. An iterative process can be utilized for the other reference hydrophones, and other known pressures and temperatures.

A display unit is connected to an agricultural implement to provide inputs and operational controls, as well as status and set up, of the implement. The display unit can be a touchscreen or other device that can receive inputs to set up, control, store information, and recall information associated with the operation of the agricultural implement. The display unit can provide a number of different types of inputs to allow for the control of the various components of the implement. Information shown, tracked, managed, communicated, or otherwise used by the system can be selected and set up by a user to customize the experience and to provide additional information useful for agricultural operations.

A display unit is connected to an agricultural implement to provide inputs and operational controls, as well as status and set up, of the implement. The display unit can be a touchscreen or other device that can receive inputs to set up, control, store information, and recall information associated with the operation of the agricultural implement. The display unit can provide a number of different types of inputs to allow for the control of the various components of the implement. Information shown, tracked, managed, communicated, or otherwise used by the system can be selected and set up by a user to customize the experience and to provide additional information useful for agricultural operations.

A metal detector detects when a target that is a desirable metal object is located within a medium. A signal is transmitted into the medium. A response signal is received from the medium. The response signal includes a secondary medium response signal from the medium and includes a secondary target response signal from the target when the target is located within the medium. The response signal is amplified to produce an amplified signal. Compensation circuitry perform transmit coil transfer function compensation on the amplified signal to produce a compensated signal. A notch module removes a resistive component of the secondary medium response signal from the compensated signal.

A metal detector detects when a target that is a desirable metal object is located within a medium. A signal is transmitted into the medium. A response signal is received from the medium. The response signal includes a secondary medium response signal from the medium and includes a secondary target response signal from the target when the target is located within the medium. The response signal is amplified to produce an amplified signal. Compensation circuitry perform transmit coil transfer function compensation on the amplified signal to produce a compensated signal. A notch module removes a resistive component of the secondary medium response signal from the compensated signal.