A footprint generator capable of applying a constant force includes: a base plate in which a target surface may be on an upper surface of the base plate; a shoe mounting member that is apart from the upper surface of the base plate and capable of mounting a shoe; a driving unit that is apart from the upper surface of the base plate and capable of moving the shoe mounting member up and down; and a force measuring unit configured to measure an impact force when the shoe mounting member descends and contacts the shoe with the target surface to generate a footprint on the target surface.

A system for measuring rigidity characteristics that measures a CT value of a golf club head based on an acceleration occurring in an impactor when the impactor is caused to strike the golf club head. Correlation data is calculated by measuring a representative CT value of the golf club head, which is calculated based on CT values measured multiple times by changing the impact velocity of the impactor, and a test velocity CT value, which is a CT value when the impact velocity is set to a predetermined test velocity, for each of a plurality of the golf club heads of an identical model. A rigidity characteristic value measuring device measures the test velocity CT value for another golf club head of the model. A computer estimates the representative CT value of the other golf club head based on the test velocity CT value and the correlation data.

A system for measuring rigidity characteristics that measures a CT value of a golf club head based on an acceleration occurring in an impactor when the impactor is caused to strike the golf club head. Correlation data is calculated by measuring a representative CT value of the golf club head, which is calculated based on CT values measured multiple times by changing the impact velocity of the impactor, and a test velocity CT value, which is a CT value when the impact velocity is set to a predetermined test velocity, for each of a plurality of the golf club heads of an identical model. A rigidity characteristic value measuring device measures the test velocity CT value for another golf club head of the model. A computer estimates the representative CT value of the other golf club head based on the test velocity CT value and the correlation data.

A measuring device for geomechanical characterization of a soil, the measuring device including a housing, a dynamic penetrometer, a power supply battery, accommodated in the housing, and an electronic system accommodated in the housing and connected to the battery. The electronic system comprises an accelerometer, as well as a distance sensor, which, in use, is oriented towards a soil and which is adapted to determine the distance between the measuring device and the soil surface by measuring the time required for a wave to travel back and forth between the distance sensor and the soil surface. The electronic system also comprises a processing unit which, when the battery powers the entire electronic system, is adapted to apply processing to measuring signals coming from the accelerometer and the distance sensor.

A measuring device for geomechanical characterization of a soil, the measuring device including a housing, a dynamic penetrometer, a power supply battery, accommodated in the housing, and an electronic system accommodated in the housing and connected to the battery. The electronic system comprises an accelerometer, as well as a distance sensor, which, in use, is oriented towards a soil and which is adapted to determine the distance between the measuring device and the soil surface by measuring the time required for a wave to travel back and forth between the distance sensor and the soil surface. The electronic system also comprises a processing unit which, when the battery powers the entire electronic system, is adapted to apply processing to measuring signals coming from the accelerometer and the distance sensor.

An object hardness measuring device includes a first side portion, a second side portion, a pedestal unit, a load unit, a measuring unit, and a holding unit. The load unit applies a load to the measurement object. The measuring unit is able to measure, in a state where the load acts on the measurement object, at least one of a movement distance of the second side portion with respect to the first side portion and a change amount of the load when the second side portion is moved either at a predetermined speed or to a predetermined position. The holding unit is able to hold the measurement object, and is movable between the first side portion and the second side portion by the slide rail unit.

An object hardness measuring device includes a first side portion, a second side portion, a pedestal unit, a load unit, a measuring unit, and a holding unit. The load unit applies a load to the measurement object. The measuring unit is able to measure, in a state where the load acts on the measurement object, at least one of a movement distance of the second side portion with respect to the first side portion and a change amount of the load when the second side portion is moved either at a predetermined speed or to a predetermined position. The holding unit is able to hold the measurement object, and is movable between the first side portion and the second side portion by the slide rail unit.

This measuring device (200), which is practical and efficient, comprises a housing (210), to be attached to a dynamic penetrometer (100), a power supply battery (250), accommodated in the casing, and an electronic system (240) which is accommodated in the casing and connected to the battery. The electronic system comprises an accelerometer, as well as a distance sensor, which, in use, is oriented towards a soil and which is adapted to determine the distance between the measuring device and the soil surface by measuring the time required for a wave to travel back and forth between the distance sensor and the soil surface. The electronic system also comprises a processing unit which, when the battery powers the entire electronic system, is adapted to apply processing to measuring signals coming from the accelerometer and the distance sensor.

This measuring device (200), which is practical and efficient, comprises a housing (210), to be attached to a dynamic penetrometer (100), a power supply battery (250), accommodated in the casing, and an electronic system (240) which is accommodated in the casing and connected to the battery. The electronic system comprises an accelerometer, as well as a distance sensor, which, in use, is oriented towards a soil and which is adapted to determine the distance between the measuring device and the soil surface by measuring the time required for a wave to travel back and forth between the distance sensor and the soil surface. The electronic system also comprises a processing unit which, when the battery powers the entire electronic system, is adapted to apply processing to measuring signals coming from the accelerometer and the distance sensor.

Provided is a system for measuring rigidity characteristics that measures a CT value of a golf club head based on an acceleration occurring in an impactor when the impactor is caused to strike the golf club head. Correlation data is calculated by measuring a representative CT value of the golf club head, which is calculated based on CT values measured multiple times by changing the impact velocity of the impactor, and a test velocity CT value, which is a CT value when the impact velocity is set to a predetermined test velocity, for each of a plurality of the golf club heads of an identical model. A rigidity characteristic value measuring device measures the test velocity CT value for another golf club head of the model. A computer estimates the representative CT value of the other golf club head based on the test velocity CT value and the correlation data.