This week I had to stand on a ladder (with no place to tie off my harness)Ā and measure horizontal distances-behind me. I'm not as flexible as I once was and it was more difficult and dangerous than I like. I used aĀ Leica DISTO after first finding a spot that was level with where I was holding the meter. Using the continuous measurement feature I watched the readings until I felt it was right. I then checked the red dot and decided whether or not to re-do.
As far as I am concerned, it was not a valid way to do a measurement, but given the circumstances it was the best I could do.
I suppose I could have balanced the Leica DISTO on the ladder rung, sighted the bubble level, measured, turned the Leica DISTO 180Āŗ, and measured again. But, I had no good way to turn it 180Āŗ. So I held the Leica DISTRO against the wall to take the measurement.
Is there a handheld meter which will only measure distance when held horizontally, or is self-leveling?
I would have preferred to use a pole to hold the meter to avoid climbing the ladder at all.
Replies
Good post! Most of us have either forgot about old techniques or were never exposed to them. Prismless EDMs have a somewhat limited range, some more than others. I have been surveying for going on 50 years & never ran across a situation that couldn't be handled by my robot in prismless mode. Fortunately, I was never called upon to make any difficult remote measurements in my transit & steel tape days. The boss usually solved problems like getting cross sections of a borrow pit in the Winter by paying some hungry, newly wedded rodman about 3 times his normal salary to go swimming. You never know what you might be asked to survey or when. I have surveyed everything from container ships to rail road car dumpers, including a buoy tender for the coast guard. As-builts obviously create the biggest need to make remote measurements. It's pretty flat here. I bet surveyors from the mountain states have some tales to tell. Three point resection & triangulation were used a lot in past years.
consider using a method an "old school" mentor of mine explained to me once.
During WW2 in the Pacific - an ad-hoc method of remote triangulation using two theodolites to speed up many surveying tasks we might not grasp. Ā Such as sighting a remote artillery target by setting up two instruments on the ends of an accurate and known baseline.
I have used this method to measure items such as overhead bridge trusses. Ā These members and structural connections were 30 plus feet above the roadway and 50/60 feet above the river surface. Ā Carefully picking out critical points and tripling my angle readings I got acceptable results.
Rick,
Thank you for the suggestion. I looked at the reviews for the 50 and 100.
The price is reasonable but the outdoors limitations worry me.
Doug,
There was no option on the measurement, it was required by the protocol.
It was my choice to use the laser on the ladder. I suspect the organization which developed the protocol expects us to use a metal tape measure. Normally, the distances are around 8-10 feet or about 2.5 to 3 meters. I just find working with a laser distance meter generally easier and more accurate. The bubble level and sight are usually sufficient.
(A coworker stepped off a ladder into a pallet and shattered his Tibia. He then drove to a site which was three hours away. When the pain became too intense, he called his wonderful wife who drove the three hours to the site and took him to hospital near home. After surgery, he texted everyone a photo of his x-ray showing the many pins and staples. I almost puked. He was out of work for months. Then shortly after starting back to work, he quit and now drives big trucks for a living.)
Not as flexible eh? From a bloke with a ladder related broken ankle which is still painful and a downright pain in the bum generally, even after twelve months...stay off the ladder. Without seeing the problem in the flesh it's hard to give an answer. Perhaps ask the person wanting the measurement to show you how or just convince him he doesn't need it. Or, last resort, and glibly, think outside the square, Good luck.