In a message dated 7/20/2009 6:09:49 AM Eastern Daylight Time, measurer@rogers.com writes:

Gene,

What is the RRTC's position on calibration courses measured by a laser? The last I had heard is that this procedure is accepted if the procedure was done by a qualified (certified to use this apparatus) person. The measurement was done at least 3? times and this distance was the shortest of the values obtained. The distance, name of the individual, name of the apparatus used were all to be stated in a letter on company letterhead (engineering firm). Is this basically still required?

The reason I am asking is that I have a group who puts on races and they are now branching in to measuring. They however have decided to purchase a laser to measure their calibration distances and I am wary of these "black boxes" in the hands of non professionals.

Pete, is this a question that should be added to the RRTC Bulletin Board?

Bernie

Dear Bernie,

A full-dress laser measurement rig like surveyors use costs several thousands of dollars. I suspect the rig your people are thinking about is a cheaper consumer model, which I don't trust, as the accuracy is not known aside from what the manufacturer claims.

I don't see the necessity, as a 300 or 400 m calibration course can be taped in half an hour or less. Moreover, the accuracy is plenty good enough for road course measurement purposes.

I'll put this exchange on the BB and we may see other opinions.

Best, Pete

I believe Justin Kuo has a laser measurer that New England USATF uses for field event measurement, which is to the nearest cm. I recall him telling me he's used it to landmark points, but not to lay out a cal course. Perhaps he will elucidate.

I measured a course for a race put on by a local artillery unit of the National Guard. The use laser transits to sight in their cannons, and brought a unit to lay out a cal course in return for my measuring their course. Easy peasy, lemon squeezy.

Sounds iffy to me. How did your riding constant compare with values obtained on other cal courses?

Pete, it seemed fine. I later steel-taped a 300m segment from one of the endpoints that I use fairly frequently. I have never measured the remaining distance, but I will do so now that you've piqued my interest.

At the time, I wasn't about to look a gift horse in the mouth, especially when said horse was hitched to several 105mm howitzers