I was browsing the local version of eBay just before Christmas and found a Wild NAK2 for $300 which was too good to pass up for very occasional use on short runs. If it's a long way between and not dead flat GNSS quicker, if it's steep robot quicker and can't see myself getting into dam monitoring anytime soon.
I know if running any real distances you'd use a digital level but for short very occasional runs does anyone have a favourite level staff?
I've always used the standard E style staves in the past but found https://www.myzoxjapan.com/products/article/22 when looking and can't see any downsides.
Get a good Philly rod for short runs. I always had good luck with those for onsite work and occasional level run to a site. Heck even ran several few mile runs with them and never had issues at all. Fiberglass are great for Topo and dipping manholes. Aluminum I am not a fan of just to impacted by the heat weather changes . Nak2 is a good level.
I hear several people make statements that digital levels for long runs but honestly you can achieve the accuracy and precision with a good level and rods reading them conventionally. The digital level makes it more convenient a digital file. Vs hand written notes.
I agree with the Philly rod for your intended use. Quick, easy and reliable.
I have to disagree with OleManRiver's statement about achieving the same accuracy and precision. I ran a lot of levels conventionally for photo control with a Leica NA2. When we got a Lieca digital level I noted the loop closures were about 5 times better than I had been seeing previously.
Considering that the OP is in New Zealand, and as such works in metric, I doubt that a Philadelphia rod is really his best choice
As for precision v digital, if you have a team that is super practiced up on 3 wire leveling maybe you can come close to matching a digital for speed and precision, but where are you going to find such a team when you need it? In today’s world digital just can’t be beat
@peter-lothian That’s not the levels fault. I agree with Norman that in today’s world digital is king. However the digital level are more accurate more convenient. I would say a team that ran levels often which is not the case today. But as we averaged about 5 miles a day that did not change when we ran the digital levels. Of course we followed the three wire rules and made certain they were within tolerance before moving. A good level at same specs digital vs non if in collimation should achieve the same accuracy over the same loop. Now I am speaking of the upper end digital levels not all digital levels are the same nor auto levels. The NAK 2 with parallel-plate micrometer is at .3mm I think the upper end digital are about the same now of course the rods play a big part huge. Invar solid one piece vs 2 pieces same with digital level rods they also have specs two pieces vs the one piece bar code rods. Now I today can’t walk 5 miles in a day without a nap but there was once a time I could. Really after a couple miles you are in a groove and that rod reading person and note keeper are in sync. The Rodman become the most important part of the whole team. If a reading is wrong the math Ck at time of readings tell you this. The bar codes with two piece rods have errors when the three wires are splitting them these studies have been done. But if I had to send crews out today for long runs I would most definitely send them with a digital level in adjustment. Less chance of a blunder for sure.
It's been well over 20 years since I bought a Philly rod, but the last one I bought (Leitz) was disappointing. The graduations were kind of fuzzy, and there was a noticeable vertical offset where the top section hit the bottom section. It wasn't nearly as well-built as my older Philly rods, was no more accurate than a Sokkia fiberglass rod, and much more cumbersome to use.
Yes using metric here so not sure the Philly rod would work.
You are right about digital levels and crews. In the region I'm in there are a number of geothermal power stations which require deformation networks to be leveled and a number of hydro dams to be monitored. The firm that does most of that work uses labourers not a specific survey crew to do the (precise) leveling which is made possible due to simplicity of digital level. Double runs good and least squares network adjustments meet client specs ( https://www.linz.govt.nz/products-services/geodetic/geodetic-software-and-downloads/geodetic-software/snap-and-concord-downloads not Starnet here as govt software free and excellent).
The Leica digital rods digital rods are dual scaled, bar code on one side and manual on the other. They are well constructed and would be future proof if you decided to go digital.
Foot note: The only disappointment I have with them is the storage sleeve, they are about a decimeter to short. This could have changed in the couple of decades since I last picked one up. The ones I have had look like old military surplus.
and much more cumbersome to use.
I would also add - much more cumbersome to transport.
Way back when I worked at a company that did more level work, the daily driver was a fiberglass rod, which collapsed down to a compact space. For larger projects we would carefully diagonal the Philly rod into the bed of the truck because its collapsed length was about 7 feet going into a 6.5 foot bed.
I'm almost certain I used a metric graduated Philly rod in college, so it should be something that can be found if you needed it.
IMO, a well maintained fiberglass or aluminum rod is fine for many projects. Just make sure the tabs that lock the sections are not getting worn out.
I just did a quick search for Philadelphia rods. In several pages of results, I didn't even see what I understand a Philly rod to be, but there were many fiberglass rods that had the associated tag word of "Philly".
https://www.hultafors.com/products/other_measuring_tools/H0133-levelling-rod-704/79422
This Hultafors folding rod was in popular use back in my days in Canada. Robust and quite compact when folded up. It seems to be a uniquely Canadian product. I've never seen one in the USA. If I did I'd buy one - if I needed a level rod.
I run a lot of levels. Multi-section rods are OK if running in a flat area. Once you start mixing high rod/low rod, errors will accumulate. I have three 3 meter invar rods, and several 4 piece 4 meter wooden rods (Zeiss/Trimble). We now only use the invar for anything that requires accuracy and is hilly, for example control for mobile lidar.
I used an invar rod to "calibrate" the 4 piece rod (4 m), where I computed a correction for each section and apply the correction automatically in processing software. But nowadays I try to avoid using the 4 piece altogether. We also have a 3 piece 3 m rod. Of course the one piece invar is a bigger hassle to transport.
Here are corrections for one of the 4 m 4 section rods...
0 to 1 m: +0.0002 m
1 to 2 m: +0.0006 m
2 to 3 m: +0.0003 m
3 to 4 m: +0.0014 m
These errors are caused by the very small gap between sections of the rod.
We ran levels using the 4 piece rod down a mountain and back up. About 150 turns. There were a lot of RTK points along the way, which were local base, dual occupation. Loop closure was 0.009 m over 8.8 km. Difference in elevation from top to bottom was 166 m. However, the levels showed a distinct bias with respect to elevation, up to 0.09 meters. Bright red thicker line (V) is the elevation (axis on right side of graph). Purple line is the difference between the raw leveling (uncorrected) versus the corrected RTK elevations. Black is corrected levels versus uncorrected RTK. Some of the RTK points had a lot of obstructions. Green is RTK with leveling versus corrected levels, which shows we achieved ±0.01 m accuracy vertically by correcting the levels.
After this I no longer used the multi-piece folding rods.
I also ran a 130 mile level line (one way, some sections were double run where no existing marks were available) in the late 80's with dual scale invar rods and a standard (non-digital) level with micrometer. This was bluebooked and followed second order class I specs . We did three wire, and read each of the two scales with the micrometer. It was all recorded in a program on an HP41. I can tell you that the digital level is more accurate and faster.
Of course, there are issues with the digital level, with sun/shadows on the rod, etc. I don't believe Trimble has made any improvements at all to the Dini12 since they acquired it from Zeiss. I think the problem is that not enough are sold for them to invest time and money into improving it. Surely, though, with advancements in electronics, optics, imaging, etc it could be made much better.
I wanted to test the Sokkia SDL1X level back in 2022, as it seems to be an improved version. We had a monitoring job in Tennessee and the Hayes rep was nearby, but he was not willing to come out to the job and let us try it. The problem with changing manufacturers is that each company has different bar code patterns, the rods are not interchangeable between them (i.e. Sokkia vs Leica vs Trimble vs Topcon), so I would have to buy all new rods.
My wishlist for "improved" digital level:
1) better functionality in sun/shadows
2) remote trigger (I have a remote trigger for my gopro that is a button I wear around my neck) or voice activated
3) auto focus
4) more data in the file. For example, with the Dini you can have either the time of the shot OR the standard deviation, but not both. Memory is cheap now
5) built in GNSS and compass to get a rough ±2 m position for each shot