An Expedition Approach - Calibration

All instruments should be calibrated daily both before and after the caving trip. This will not only allow correction of instrument inaccuracies but will pick up any damage caused to instruments before further surveying trips are wasted.

A simple calibration method is to set up two stations at the camp, away from electrical interference if using DistoX, and taking forward and back readings of both azimuth and inclination. The distance between the stations will be fixed so any tape or disto errors will be spotted.

It is not normally required to do a full DistoX calibration unless batteries are being changed or you have moved to a new area, but the simple calibration will alert you to any major error.