Most mine geologists seek data on four key drilling criteria: hole angle and deviation; location of reef intersections; rock temperature; and magnetic field strength. While his information needs are the same today as they've always been, new electronic survey equipment now available means he can expect a manifold improvement in the accuracy of that information, reports Boart Longyear Drilling Services Division project manager Dries Levey. Eighteen months back, exploration drilling specialists Boart Longyear CDD invested in the latest Reflex Multishot Electronic Survey Equipment as part of its initiative to keep pace with customers' growing needs for ever faster, more accurate survey data.

"While our expertise meant we were able to produce acceptable readings with conventional compass photography (a laborious process that involved photographing compass readings to determine hole direction and inclination), this new technology has enabled us - and our customers - to take a quantum leap," explains Levey. Capable of taking up to 1 498 different readings at a drill site, the Electronic Survey system consists of a hand-held terminal connected to a sensor package via a serial communications cable. Once the required readings have been taken, the data is simply downloaded into the hand-set, carried to surface and sent directly to the customer's computer for analysis. "The information can be saved onto a spreadsheet and printed, or imported to sophisticated analytical programmes. There's no more cumbersome photographic processing and now the veracity of the information is assured to a point of a degree," says Levey. "It's transfer technology at its best." Says one impressed customer, the geological manager at a prominent South African mine: "Electronic surveying has extremely positive spinoffs. In contrast to the mechanical methods we've employed until now, which are both prone to error and require skilled interpretation of the photographs, this is a far faster and more accurate method. In future, we'll be surveying all boreholes this way."