CALIBRATION VARIATION ON SHORTER CALIBRATION COURSES
The experiments conducted to date seem to lead to the ideas that:
1) The constant obtained on a short calibration course will be, on the average, about the same as that obtained on a longer one, and,
2) The variability of calibration gets larger as the calibration course gets shorter. A one-count difference on a 100 meter calibration course will have three times the effect on the constant as it would on a 300 meter calibration course.
While further shortening the length of the calibration course would probably have little effect on the average accuracy of the courses produced, it would increase the variability of their lengths. We would see more deviation from the average, resulting in more courses failing validation and more that are extra long.
When the length of the calibration course was originally reduced from about 1 km to 300 meters, it was in response to a genuine problem. The labor to lay out a kilometer was discouraging. Moreover, straight kilometers were hard to find. Changing to 300 meters solved this.
There is not much layout labor saving from 300 meters to 100 meters. The remaining benefit seems to be that 100 meters is more readily available than 300 meters. In the two decades that have passed since the original change was made I had not heard that it was hard to locate a suitable 300 meters, until Neville brought it up.
The proposed change would have an adverse effect on course accuracy without a great benefit to the ease of measurement. I don’t believe the benefit is worth the cost.