Calibration

Calibration Procedure

Reduct pipeline mapping probes are manufactured and assembled using state of the art machinery and the best materials and components. The primary nine inertial measurement sensors are mechanically assembled such that they are placed as accurately as possible on the X, Y or Z axis of the probe. However, all mechanical assembly is invariably imperfect, i.e. the angles between the nine key inertial sensors are not exactly 90°. The objective, therefore, of the Reduct calibration procedure is to measure the angular errors and compensate them mathematically.

Over a period of about two hours, the DR-CR-002 calibration robot moves a probe through over 440 static positions and dynamic moves in an inclination range between -60° to +60° (red arrows) while rotating the unit 360° around its X-Axis (yellow arrow) and 360° around its Y-Axis (blue arrows).

A perfectly assembled system calibration data yields perfect sine curves. The probe's calibration data is compared to the perfect sine curves. Then, a series of proprietary algorithms will calculate mathematical adjustments until it finds the best fit to the perfect sine curves.

As a final check the probe's performance is tested on a fixed track. The probe is passed through the track in both directions and moving forward as well as backward. The repeatability of these measurements must be high: the spread (as a percentage of pipe length) on the XY-plane may not exceed 0.25% and in the Z-plane may not exceed 0.10%.