The Joint Inspector is mounted onto the frame of the grab after it has reached the final excavation depth of the panel. The grab is then lowered to maximum depth and moved upwards along the joint. The sensors of the Joint Inspector monitor the exposed joint during this upward movement.
It takes 10-15 Minutes to mount the Joint Inspector onto the grab. A measurement from a depth of approximately 20m typically requires 5-10 minutes.
The angle of the measurement arm to the exposed joint is recorded and used to calculate the distance to the joint.
Excess concrete is detected when the sensor records discontinuous surface profile. The graphic images depict the joint surface of the adjacent panel – either vertical, displaced or twisted through torsion from the concrete.