A method and apparatus for calculating line sag in a span of a conductor is provided. The method includes using a portable smart device having one or more accelerometers and running a line sag application on the processing device. The line sag application enables acceleration data of return waves generated on the conductor to be collected using the smart device and to be plotted as a function of time for display on the smart device. The method further includes placement of time markers on the plotted data displayed on the smart device to determine elapsed time and calculating line sag using the elapsed time.

A method and apparatus for calculating line sag in a span of a conductor is provided. The method includes using a portable smart device having one or more accelerometers and running a line sag application on the processing device. The line sag application enables acceleration data of return waves generated on the conductor to be collected using the smart device and to be plotted as a function of time for display on the smart device. The method further includes placement of time markers on the plotted data displayed on the smart device to determine elapsed time and calculating line sag using the elapsed time.

Disclosed is a sheave for use in a tension measurement system to measure a tension force in a cable. The sheave includes a first diameter and a second diameter. The sheave is configured to rotate about an axis to orient the first diameter or the second diameter toward the cable, such that a contact force between the sheave and the cable is measured by a tension sensor to determine the tension force in the cable.

Disclosed is a sheave for use in a tension measurement system to measure a tension force in a cable. The sheave includes a first diameter and a second diameter. The sheave is configured to rotate about an axis to orient the first diameter or the second diameter toward the cable, such that a contact force between the sheave and the cable is measured by a tension sensor to determine the tension force in the cable.

The invention relates to a method for defining a tension of a belt of an automatic door. The method comprises: exciting a resonant frequency of the belt to cause a vibration of the belt, obtaining motion data representing motion of an electric motor configured to move the belt, defining vibration information representing the vibration of the belt based on the obtained motion data, and defining the tension of the belt based on the defined vibration in-formation and predefined characteristics of the belt. The invention relates also to a door drive unit and a computer program for defining a tension of a belt of an automatic door.

The invention relates to a method for defining a tension of a belt of an automatic door. The method comprises: exciting a resonant frequency of the belt to cause a vibration of the belt, obtaining motion data representing motion of an electric motor configured to move the belt, defining vibration information representing the vibration of the belt based on the obtained motion data, and defining the tension of the belt based on the defined vibration in-formation and predefined characteristics of the belt. The invention relates also to a door drive unit and a computer program for defining a tension of a belt of an automatic door.

A containment force apparatus and method a containment force apparatus for measuring containment force on a load, the apparatus comprising a first element configured to contact the load; a second element configured to engage at least a portion of a packaging material on the load and move between a first position associated with the first element to a second position perpendicular to the first position and spaced from the first element a measured distance; an actuator configured to urge the second element to move between the first position and the second position; and a force sensor configured to measure a force exerted on one of the first element or the second element.

Disclosed is a sheave for use in a tension measurement system to measure a tension force in a cable. The sheave includes a first diameter and a second diameter. The sheave is configured to rotate about an axis to orient the first diameter or the second diameter toward the cable, such that a contact force between the sheave and the cable is measured by a tension sensor to determine the tension force in the cable.

Disclosed is a sheave for use in a tension measurement system to measure a tension force in a cable. The sheave includes a first diameter and a second diameter. The sheave is configured to rotate about an axis to orient the first diameter or the second diameter toward the cable, such that a contact force between the sheave and the cable is measured by a tension sensor to determine the tension force in the cable.

Systems and methods for testing cable bending fatigue include a hollow body for at least one cable to pass through, a pair of primary gears, respectively located at both ends of the body, and connected by a transmission shaft and can be driven to rotate by a first motor via the transmission shaft, and at least one pair of secondary gears, each pair of secondary gears being respectively meshed with the pair of primary gears, and drivable to rotate by the meshed primary gears, wherein, both ends of the cable are respectively fixed to gear centers of a respective pair of secondary gears, and the body causes the cable in a bended state when both ends of the cable are fixed to the gear centers of the pair of secondary gears.