In order to take the reading on the dip, you have to be in line with the hole and when you are checking a ring it becomes apparent whether you are lined up on the ring or not.
It takes an interest and effort to do the work and in most mines there is not an interest to do this basic work; may because it is too often assigned to surveyors who have other priorities. The people doing the blast layouts, those with a vested interest in seeing the blast come out well, should be the ones taking these readings in my opinion.
- For upholes you have to bend back (see attached photo) some people don´t like to do that.
- For downholes you have to dirty yourself by pulling out the cones one by one, then you have to take off your gloves take the reading and put the cones back. Can take a number of hours to check a stope.
- This opens up another opportunity, that of checking at what depth downholes start to deviate. With a flashlight in the hole, it makes it much easier to take an accurate reading.
Recommend doing it with two people, because one can illuminate the dial, take notes, figure out which hole you´re on and leaf through print outs of the drill sections. The other person shines the light up the hole and shouts out the reading. It is possible to illuminate the dial and shine your light up the hole but it takes a bit of skill.
The timing of when you take these readings is important. No point in waiting until after the drill has moved out; so this is somethings that should be done as the drill is working. The mere fact that someone is seen to be checking the rings will, in itself result in improved drilling.