level recommendations

Dane,
we still use our Leica NA2, and a long time ago when we did high precision work we mounted the parallel plate with micrometer. Never used an invar-lath.

chr.

I've used an older Zeiss DiNi11 with very good results. We have both one-piece invar rods and folding wooden rods. Once you get used to a digital level you will never want to read a rod again. A properly running crew with three men can level almost as fast as they can walk.

Peter Lazio

I've used a variety of brands and models through the years. I currently have a Wild NAK 1 that suits my needs just fine.

Dane, what NGS order and class of leveling are you trying to adhere to?

3rd order. It is not likely that I will ever need to do first order work. But perhaps I should consider a level that could produce results acceptable for second order.

The DiNi 0.7, which I'm guessing is equivalent to the older DiNi 22, and an aluminum bar code level rod is probably what you are looking for. We routinely are able to achieve 2nd order NGS type results even though we are only following NGS 3rd order procedures. This is also probably the cheapest option. I'm not sure why these guys are using invar rods unless they are bluebooking for NGS.

Another alternative you should consider is the DiNi 0.3, which I am guessing is equivalent to the Dini 12 and is a 2nd order level. You could also use with an aluminum bar code rod and if the need ever arises that you need to do something more accurate, you could then obtain a wood or invar rod to use with this level. You'll have to get the invar rod calibrated before you can use it to bluebook anything though.

What least squares adjustment software do you use? You should make sure that you can convert the raw data file from a Trimble DiNi (or whatever the Leica equivalent is) to your LSA format. We use Star*NET. Other than Leica or Trimble, I don't think I would consider anything else.

Right now I personally use a DiNi 12, 20 (Zeiss), and 22. We almost always use them with aluminum bar code rods, though we have several wood folding rods that we break out for the special occasion for high accuracy work. Most of our work is for the state DOT doing road design and structure surveys. And all this equipment is well within their specs.

We used a Leica NA 2000 for about 10 years, and generally got 2nd order closures, with the fiberglass rod. We have since upgraded to a Leica DNA 10. We still get similar closures. We have to do settlement surveys on an earthen dam each summer. Because of the chance of slipping down on the rip-rap, we have considered getting a Sprinter for that survey, and considering it disposable. We damaged the NA2000 in 98' and it cost the same as a Sprinter to get it fixed. Before digital levels, we used Ziese (spelling) NI2 levels.

JoeM

I would be using Star*net for adjustments. So it is good to know that Trimble will work with that adjustment package.

JoeM

I favor a regular level you look through. When I need a level I have an old Zeiss Ni2, it always works as long as I can see the rod.

I use a Topcon digital level but it seems more trouble than it is worth. It is picky.

levels

I'm glad I'm not the only one that thinks that way. I don't do level runs on a daily basis or for high accuracy work generally, but I have done subsidence monitoring with a regular old optical Leitz level estimating the shots to a regular old wooden level rod to the thousandths with short shots and gotten amazingly good results. A really long level loop for me is 15-20 turns and if I close within a couple of hundredths, the math is not that challenging to adjust the loop with a pencil. I have demo'd a Topcon digital level at the insistence of the salesman who had made it his goal to sell me one. I was underwhelmed with the advantages to say the least.

Steve

but leveling is so unbelievably complex, obviously you are just a Luddite! 😉

Really, technology is great and everything, but sometime old tech is the best tech.

I think if you want to follow NGS specifications now you have to use a digital level.

Dave

The Ziess Ni-2 is my favorite optical automatic level. Just ahead of the Wild/Leica NA-2 and the Sokkia B-1.

Stephen

the one we have is a little weird. The stadia hairs are set up for a Yard rod. Apparently that is what the old Division of Highways used.

We use a Leica DNA03 which is speced for 1st order work. I'm not sure what the Trimble equivalent is. If I recall it was a couple of thousand dollars more than the DNA10 but since we were doing a lot of work for NOAA at the time it made sense. The DNA03 has a couple of special programs that follow the NGS guidelines.

As for digital versus conventional levels, if you only pull it out of the box for a couple of turns at a time the old school wins out. If on the other hand you need to run tight vertical control for long distances, go digital.

John

> We routinely are able to achieve 2nd order NGS type results even though we are only following NGS 3rd order procedures. This is also probably the cheapest option. I'm not sure why these guys are using invar rods unless they are bluebooking for NGS.

I infer that the phrase "NGS type results" means meeting the FGCS closure specifications (e.g., 12 mm times the square root of the distance in km for third order work). It is, in fact, possible to achieve this with a digital level and an aluminum rod. It's also possible to achieve it with a stadia board and a hand level. Hitting the closure spec doesn't say anything about the accuracy of the intermediate turning points.

The NGS/FGCS leveling specs describe equipment, methods and conditions, all of which must be met in order to reasonably ensure that the associated accuracies are attained. With digital levels and barcode rods, closures tend to be excellent, largely because rounding errors are smaller and more randomly distributed since human judgment isn't involved. But don't expect to achieve FGCS accuracies just because you're using a digital level.

I have a Leica DNA03, and use it for runs longer than a city block or two. I almost always use it with a 3-piece fiberglass barcode rod, and get results that are good enough for the kind of engineering design topos I typically do. (I also own a Lieca invar rod, but have yet to use it on a paying job.)

For miscellaneous leveling, like construction staking or Elevation Certificate shots, I use an optical level (Topcon AT-G2) with a 25-foot fiberglass rod and a field book. It produces acceptable results, is quicker to setup and operate, and doesn't need batteries or downloading.

Yes your inference is correct, I can meet NGS 2nd order closure specs using 3rd order equipment and procedures. Dane was looking for recommendations on a digital level. I have no idea what he is going to use it for. I was just telling him what I use and how it works for me.

David

Another thing to watch out for is some of the European models have stadia set in meters.

Stadia set in meters?

The stadia hairs are set as a ratio, they are unitless. A typical level has stadia hairs set at a 1:100 ratio, so if you intercept 1 m, then it is 100 meters, if you intercept 1 foot, then it is 100 feet.

Digital levels are the greatest thing since sliced bread, but they can be finicky under varying light conditions (i.e. shadows, poor illumination,etc.)

I have used both Leica and Zeiss (now Trimble). Either will work fine. I had a bad experience with a Topcon digital, I would assume they have improved since then. But, I would stick with Leica or Trimble.

I, like Mr. Putnam, use a DNA 03. The 03 refers to the seconds of the digital level, much like a regular total station. I think that Leica has both the 3" and 10" digital levels. I really like the DNA 03. Fast easy and nearly dummy proof. In terms of accuracy, if we close back in to our original bench usually about .005' worth of error. anything more than that and the rodman needs to learn how to set his temporary bench, but with a good bench, it is as nearly flat as I have seen. DNA 03 runs about $5000. Worth every penny. Good Luck!!