Opinion - How Close Can We Set a Monument

I think it also depends on how plumb you can drive the rebar, most of the time I can drive the rebar straight down, others times I had to pound on the ground next to the rod to get the Cap where it needed to go, also in a gravel road, it goes where it wants to go.?ÿ

Exactly - one reason why the equipment is not the limiting factor.

I remember this old argument...

The answer, from a long time ago, was 0.04'

If I get a rebar within .02 while setting I call it good. Adding in rod plumb error, rod wiggle (not holding steady) and traverse error, I would say I'm within .05 most of the time. Plenty close for what I do.

I mostly do urban/suburban work, and I try to get the monument within 0.02' of the desired location.?ÿ (The post-processed position of the monument sometimes comes out slightly father off, but rarely more than 0.03'.)?ÿ Using a copper disk in concrete makes it pretty easy to set the punch mark inside that tolerance.?ÿ Rebars are more challenging, but I try nonetheless.

Nobody ever accused me if working fast, though.

Posted by: Jim Frame

Using a copper disk in concrete makes it pretty easy to set the punch mark inside that tolerance.?ÿ

Those copper disk are great. Thanks again Jim for responding to my questions about these markers a year or so ago.?ÿ

Sorry for hijacking the thread....?ÿ

2" caps are important ??ÿ

Just like "how accurate can you measure?

How much of my time and equipment do you want to pay for?

Many of my surveys start with a stone mound.?ÿ I have several feet of slop before I even get into setting corners.?ÿ But when it comes to putting metal into the ground, my goal is to have my equipment tell me I am within 0.02', and I try to rotate the rod around so I can verify if my rod might not be plumb ( I do forget sometimes).?ÿ But I also realize not every rod can drive straight, not every measurement is as accurate as the manufacturer claims, wind does gust sometimes, or a horn startles you, or all kinds of other little things that make up our imperfect world.?ÿ

Iƒ??d say under ideal conditions 0.02. ?ÿIƒ??d say 0.04 is the norm and Iƒ??ve seem a lot worse.?ÿ

He said bar or pk.?ÿ How about for the nails?

You can only set a mark as accurate as the control that dictates where the mark is to be set. Anybody can precisely pound a marker at a given distance.?ÿ

Posted by: RADAR

I remember this old argument...

The answer, from a long time ago, was 0.04'

I thought that was the answer to ƒ??how far off does a mark have to be before you reject it.ƒ? Dang... itƒ??s getting harder and harder to keep up.

I will not walk away from the monument unless it is 0.03 or lower.

For monument 200ft or less apart I want them as close as possible 0.02ft max and for all the rest 0.04' at most.

I do not set points in a road unless it is absolutely necessary as they move around from many factors.

Hubs are shot on forsite with a target on tribrach on tripod and with same setup shot again on each backsite.

A bad setup is found quickly.

The tolerance is dependent upon the location of the land between rural areas where 0.04 is alright to downtown where it needs to be spot on.

0.02

3 times the inverse of the property value (in thousands of dollars per acre), not to exceed a half link...

If you get the data collector stakeout to read 0.01' or under you can assume that you are within about +/-0.03'. If you quit when your dc says you are +/-03' feet then you are likely within 0.10'.?ÿ By this I mean how close the next guy, who is doing his work equally competently, will find your points to be.

I regard the stakeout number to be a standard deviation (1 sigma), and the other guys recording will be within 3 sigma (99% confidence)?ÿ?ÿ

It depends on the level of self-deception you allow yourself.

Mark, I like your answer.?ÿ Let me ask you another question.?ÿ When you go to stake a property corner and you find another one already there, how close does the found corner have to be to be considered the "same" location that you have calculated (this is NOT a math question)?

?ÿ?ÿ