A laser tape measure works by calculating the distance between two objects using precision optics and laser physics. Calculations are performed using a phase-shift method that compares the reflection of the beam the laser tape measure sends out when it hits an object. Some laser tape measures use the time-of-flight method to determine the amount of time it takes for an optical pulse to reflect back to the tape measure.
To use a laser tape measure, place it at the end of the object that is being measured and aim the laser beam so that it hits another object at the other end. Press the button to active the tape measure when the laser is in the correct spot. The tape measure calculates the distance between the two points and displays a reading on its screen.
A laser tape measure is used to calculate lengths, widths and heights up to approximately 650 feet depending on the tape measure that is being used. The devices are accurate to within 1/8-inches when measuring distances 300 feet or less. Laser tape measures are considered to be quicker and easier to use than conventional tape measures because they produce more accurate measurements and are easier to read.