Three water districts begin field trials with our magnetometer

Three water districts are now using our portable NV-diamond magnetometer to survey recharge areas. The instruments were built in our shop, calibrated on site by district staff after a two-day training, and are now collecting weekly transects.

Fieldwork is a different discipline from laboratory metrology. A sensor that drifts by a few picotesla in a temperature-controlled room may drift much more in the back of a truck. The trial has already produced a revised magnetic shielding design, a simpler calibration procedure, and a new appreciation for the person who has to carry the battery.

The districts own the data and decide what to publish. Our agreement gives them a veto over site locations for privacy reasons, not over results. We will publish the instrument performance and the failure logs; they will publish the hydrological interpretation if and when they choose.

Two units have failed in the field so far: one from a cracked optical mount, one from water ingress after a storm. Both are documented in the public issue tracker, with photographs.