FIELD: physics.
SUBSTANCE: ultrasonic signal is passed through a reinforcement bar, the phase of the signal at the output of the bar in unloaded and loaded states is measured and elongation of the bar is determined using the formula: 
where: Δφ=φ2-φ1; φ1 is the phase of the signal at the output of the reinforcement bar in unloaded state; φ2 is the phase of the signal at the output of the reinforcement bar in loaded state; c is speed of ultrasound in the reinforcement; f is the frequency of the signal.
EFFECT: high accuracy of measuring elongation of reinforcement, low power consumption, possibility of monitoring elongation of a reinforcement bar in a finished reinforced concrete structure.
2 dwg
