A vibration sensor for construction and industrial projects, comprising: a water-proof housing; a low range accelerometer disposed in the housing; a high range accelerometer disposed in the housing; an analog-to-digital conversion circuit connected to the low and high range accelerometers; and an interface circuit disposed in the housing, or a communication circuit disposed in the housing and in communication with a computer external to the housing; characterized in that the interface circuit or computer is configured to such that: (a) if the measured acceleration data from the high range accelerometer are greater than a first threshold acceleration, the measured acceleration data from the high range accelerometer are used to calculate velocity information, and the data from the low range accelerometer are discarded; (b) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are smaller than a second threshold acceleration, the measured acceleration data from the low range accelerometer are used to calculate velocity information, and the data from the high range accelerometer are discarded; (c) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are equal to or greater than the second threshold acceleration, the accelerometer whose acceleration data were used in the previous velocity calculation is selected and the current measured acceleration data from the selected accelerometer are used to calculate velocity information, and the data from the other accelerometer are discarded. a water-proof housing; a low range accelerometer disposed in the housing; a high range accelerometer disposed in the housing; an analog-to-digital conversion circuit connected to the low and high range accelerometers; and an interface circuit disposed in the housing, or a communication circuit disposed in the housing and in communication with a computer external to the housing; characterized in that the interface circuit or computer is configured to such that: (a) if the measured acceleration data from the high range accelerometer are greater than a first threshold acceleration, the measured acceleration data from the high range accelerometer are used to calculate velocity information, and the data from the low range accelerometer are discarded; (b) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are smaller than a second threshold acceleration, the measured acceleration data from the low range accelerometer are used to calculate velocity information, and the data from the high range accelerometer are discarded; (c) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are equal to or greater than the second threshold acceleration, the accelerometer whose acceleration data were used in the previous velocity calculation is selected and the current measured acceleration data from the selected accelerometer are used to calculate velocity information, and the data from the other accelerometer are discarded. (a) if the measured acceleration data from the high range accelerometer are greater than a first threshold acceleration, the measured acceleration data from the high range accelerometer are used to calculate velocity information, and the data from the low range accelerometer are discarded; (b) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are smaller than a second threshold acceleration, the measured acceleration data from the low range accelerometer are used to calculate velocity information, and the data from the high range accelerometer are discarded; (c) if the measured acceleration data from the high range accelerometer are equal to or smaller than the first threshold acceleration and the measured acceleration data from the low range accelerometer are equal to or greater than the second threshold acceleration, the accelerometer whose acceleration data were used in the previous velocity calculation is selected and the current measured acceleration data from the selected accelerometer are used to calculate velocity information, and the data from the other accelerometer are discarded.