A "hands on" feel channel for best practice tutorials, lean concepts and methodology for the world of Construction Surveying, Field Engineering and other trade professionals utilizing field layout techniques.
leanSurvey is a consultant and training content developer for Elevate Construction IST. Visit elevateconstructionist.com for information on professional and technical training, boot camps and much more.
This video should have included a warning that sideshots should always be observed twice. Mistakes can happen easily if you accept a single reading at face value. Whenever I have to read a dozen points from one setup, I will backsight, perform all of my sideshots, break on the final sideshot, then observe them again going backwards before closing my run. Credit where it's due, your explanation of leveling is very straightforward and easy for rodmen I have worked with to understand.
@@dikemawson3008 Thank you. HARD AGREE on that comment as well, taking a reading, look up, take it again to verify for single wire. For three wire, checking your reading math (delta between top middle vs middle bottom) is your double check- because then your readings are mathematically verified, not just visually. I also recommend your method of running back through the same points on your way back to the benchmark, not only does it QC and average your elevations, but if an error or misreading did occur, its clearly highlighted by the doubled up data AND correcting it is confined to repeating the one setup as well. Great thoughts!
@@MortezaEzadipanah This content is at the fundamental level for persons performing layout or grid line QC such as field engineers or survey technicians working inside the building. Robotic layout although utilizing much more expensive equipment is not as accurate at conventional work with corrected angles. Even the most expensive piece of equipment still has a feature to double angles for increased accuracy. This is no different. And it is about 30 thousands of dollars less expensive.
This was a great video. Every beginner in site work should see this video. Only thing that still confuses me a little is current terms for the same thing like, benchmark known height, height of instrument. Almost need a dictionary for tems....
@@patmccluskey7504 Great feedback, thank you. I’ve been trying to replace the term “height of instrument” with “the elevation of the level line” even though height of instrument or “HI” is such an industry term, it doesn’t translate that well when teaching at the beginner level. I’ll think about glossary of terms videos for different applications, that’s really smart.
Great video but what I would have done to make the math easier is when looking through the level at the backlight I would have turned the screws all in the same direction to lower it to eliminate that .003 and get a round number rod reading of 5.22.
@@littlenel17 You’ll notice in all my level in videos, I promote rounding to the thousandths when operating a builders level (though not a laser level). As a result, I would not spend extra time dialing in my first reading when all my subsequent math and reading would contain thousandths anyway.
@@leansurvey8212 it makes sense…for elevations on benchmarks we just go to the hundredth…the laborers dont want to deal with splitting the dashes on a Philly rod
@@mattymattareeno4326 a prism sits in a small canister, right.. there is the flat face of the glass, and then the facets of the prism converge further back in the canister. The prism is always intended to be tilted toward the equipment when operating but when you are aiming across a site, it’s easy for that rotation to be a little off. You get more viewing angle (allowing your rotation to be less perfect) when your prism is mounted recessed at 30mm. At zero, you really have to aim near perfect or else the canister housing blocks the facet convergence point much more easily and you are unable to get a prism reading. It definitely happened for a reason, that’s why 360 prisms are taking over, no more rotational worries.
@@wesalnawabi5775 I love the recommendation of an animation, great idea. You will actually see animated segments in many of my future videos.. this is one of my oldest, don’t be too hard on me ;). Fortunately, many of the other viewers and commenters seemed to have gotten the gist. I’d also like to post up a video on simply setting an elevated line or target. More (and better) to come!
Did you take only the one reading on the form or did you go around the corners to make sure the for was the same height all around? So if the laser gives a somewhat imprecise reading and (knowing optics) it widens out over distance, making it even less accurate, what are your thoughts on what range is useful for a laser level before error starts to become excessive.
@@bwhog Well, this was primarily a training video, so I only shot the two items. When doing the real task before filming, I setup in the center of the bldg form so that my shot to the backsight was the longest shot taken during the course of the work (which was still less than 200 feet) and all my other shots at the 4 corners fell inside that backsight distance. Working inside your backsight distance is a great way to ensure you are not extrapolating errors, especially when the backsight distance accuracies are already at or near your task tolerance or max instrument capabilities. Great question!
Great video. Can you expand on this topic to the procedures for setting building stakeout elevation with the level. Proposed grades. Keep the videos coming. They are really helpful.
I’ve got a video about laser level basics coming out in the morning that I think will answer the question you are asking. Let me know if it doesn’t and we’ll dial in your specific question.
01:25 I can accept rounding to the nearest hundredth but estimation seems fraught with problems. I saw a method of doing this not too long ago that basically made rounding errors all but cancel out. In your example, you have rounding errors of +.004, -.003, and -.002 for a total of -.001. That doesn't seem unreasonable. Yeah, this specific case, but still... (I'm from an engineering background and the practice in a lot of areas is that you never try to estimate beyond the precision of the gradations of your instrument because you can never do so accurately. Even mathematical interpolation is often frowned upon.)
A concept which could be better explained is to what decimal place you “publish” values. Most plan sets and most published datum report to 2 decimal places. If you will accept rounding, then why not estimate to the thousandths during the course of your work, your notes, your data (or if you don’t like the word estimate, lets call it: take a reading to a higher degree of accuracy- because no matter how you slice it a reading to the thousandths will be tighter than a numerical value rounded at every reading) but then when you publish, publish to 2 decimal places. Then you will have taken tighter readings throughout and your final rounding (which you already believe in) will be satiated upon publishing. I also only publish to 2 decimal places because what subsequent trade will even have the equipment to perform worth tighter than the hundredths place or two decimal places. Just so you know, I’m not being sarcastic with you, this is my actual practice. Perform work to the thousandths, keep the figures extremely tight throughout- and then publish to 2 decimal places. As an engineer, dont you sometimes use coordinates or other values to the highest reported decimal place in CAD or in a CSV file, even though the methods of recording likely don’t warrant that thousandth? Because the instrument, CAD and CSV exports estimated that 3rd or even 4th decimal place. Why not take advantage of it when your eyeball is capable of the same?
You forgot to add, after placing the target, going back to the level to make sure you positioned it properly. I'll also mention that a method of getting that last thou or two can be to turn your leveling screws all in the same direction a quarter or half turn or something to use them to slightly lift and lower the instrument.
@@bwhog I actually want to create a video for setting a target card without bucking in, just transferring marks and measuring up or down from the level line. I’ll be sure to show the whole process there. Regarding the 1/4 turn that works, I prefer to use the tripod to raise lower and the screws to level. There are definitely areas where someone else (or several someone elses) have a great method. In that case, I say whatever works, or better yet, whichever is fastest. Thanks for the great comments!
How often do you go through your instruments to make sure they are in calibration? Do you like schedule an annual "Equipment Check and Refresher Day" for all the guys in the office once a year or what?
@@bwhog Definitely depends on the instrument or any displayed symptoms. I say if you are in the GC world, every time a new project starts, in the civil/survey world, annually… HOWEVER, I recommend pegging your level yourself every 3 months or any time it has been out of your hands for too long (like loaned to another trade or team mate) and running the field calibration for the horizontal and vertical angles on a total station at the same 3 month interval. I can’t tell you how many times over the last 25 years of surveying I have loaned something out which was then dropped and not reported.
@@leansurvey8212 So, in the same vein... recent discovery for me... Have you or anyone you know ever made use of the Crosscut EDMI calibration baseline? Found the benchmark almost grown over with grass.
I have an interest in vintage instruments. Ever consider doing a video series on how things used to be done? Like, say, best practices and accuracy of a 1 minute theodolite, chaining old school, etc?
@@bwhog From a bandwidth standpoint, I’m already turning out videos much slower than I’d like, so I’ll probably stick to more current topic sets. Fun though. In the survey room ASU’s school of construction there are a bunch of old military theodolites in the green “tank ordinance” sleeve.
Is it always necessary to use a penetration to accomplish this? (and what method do you use to ensure your penetration will be directly above your lower floor bench mark?)
@@bwhog That feature also needs a video. A PLS or similar vertical laser from mark on the floor below projected onto the deck of the next floor, then drive a screw partially through the deck. Then a PVC sleeve cut to the correct deck thickness is taped or wired into place where the nail pokes through and the opening is covered with duct tape. After the pour, you just poke the tape out and you can project that as many floors as needed. You could also perform this work when only half the deck was poured and avoid penetrations at all. Just putting this idea out there as an option since many folks are pulling from a 4’ above FF chalk line that no one knows how it was set or god knows who’s crows foot mark with an elevation written next to it in a door jam.
What would you include in a resume that really stands out? I want to move up in position from Rodman to crew chief. I know almost everything there is to know thanks to my crew chief. however I don’t want to waste my youth waiting for someone to step down especially when I see constant mistakes being done from the instrument man along with other people which I find really really easy and simple. I want to be put to the test, And I want to show people how much better I can do the job. right now I’m doing construction surveying But I would love to move to a bigger company with better pay and more opportunities to grow. I live in Dallas Texas if anyone has any recommendations please let me know
@@jorge-l4h When you say ‘what to include’ I dont know if you mean what should I say or what should I learn. I recommend getting to know CAD and learning to process your own calcs and your own topos. The better you know the whole process including what the drafting tech or civil is ‘thinking’ you can fill their needs better. One of the roughest parts of the industry is too many middle men between the actual needs of the civil team (or the project team on site) and what the surveyor does out in the field. Second, ask your crew chief if you can run the check in and check out with the project team when hitting a construction site. The more you make yourself a part, the more they will ask for you, the more they will teach you, the more they will come talk to you instead of calling in when something goes wrong. Specifically read the job description for yourself everyday. As your chief if they will let you plan the day. On your resume write “crew chief in training” describe what you know, especially once you can factually say you are setting up work and planning your days, your resume needs to call that out loud and proud. Apply for chief or junior chief roles, now. Even though you do need to be aggressive in your resume, nothing is more important than getting that interview and showing them that you want it. Don’t ever pretend that you know things you don’t, but always communicate you are ready to learn and take that learning seriously. Don’t just email a resume. Call the office, get team lead names. Call later and ask for them directly, see if they have had a chance to read your resume and if not see if you can send it to them directly. Aggressive might be irritating, but it also put you in the front of peoples brains and lets them know you are hungry. Good luck, you’re on the right path already!
@@jorge-l4h great idea! I’ll work on this. In the meantime, my book Elevating Construction Surveyors covers this topic quite thoroughly and is available digitally and on Amazon.
Man... never ever ever take your hand off the handle until its threaded. If you think holding the tribrach is good enough, I've got construction sites that beg to differ.
The method in this video works, but takes too long (IMHO) because lots of surveyors want to utilize the optical plummet of an instrument before it is leveled true. First, this video shows a "wide enough" stance, where I see a lot of people who set up this way end up with the tripod base that is very narrow. By "this way" I am referring to a setup procedure that includes at some point, looking thru an optical plummet that is not plumb/level. Those narrow set ups (the one in this video not included, it is fine) can "blow over" especially working along an interstate highway and set up in the breakdown lane on asphalt. So, first, I suggest a setup with the height pretty much as in this video (relative to your own eye height and the terrain) but the legs even further apart for a wider stance (video setup is very good, but wider is even better). There is no reason (95% of situations) to not have a maximally stable stance. That being said, the following method will get you set up in sixty seconds or less nine times out of ten. This setup time begins only when you are more or less at or very near the setup point. 1. Extend a leg to your preferred length (I suggest a couple tenths longer than was done in this vid, (becuz even more stability), and then drop the other two legs to the same length. 2. Place the tripod somewhere and attach your instrument to it (this step is only needed at your first setup, but every setup if you box your instrument between setups). I transport my instrument between setups on its tripod, and I carry the assembly upright, so as not to stress the total stations structural parts. 3. Place one leg an appropriate (educated guess) distance from the setup point, and take the other two legs in your hands about midway down each leg. Open the legs so that they are splayed to either side of you, in more or less the desired angle with the tripod head ROUGHLY eyeballed as level. 4. By eye, imagine a plumb line passing through the instrument, and move yourself and the two loose legs so that imagined plumb line also passes through the leg that is touching the ground AND the setup point. That is, you are moving the two loose legs, and your head and body and the instrument, so that your eye, the opposite fixed leg and the instrument are all somewhere on that imagined plumb line that also passes thru the setup point. 5. Set down the two legs you were holding and moving, taking care to keep the tripod head roughly level (roughly, don't bother looking at the bubbles). 6. With all three legs on the ground walk around the setup a third of the way, and note that, from this new vantage point between a different pair of legs, an imaginary plumb line passing thru the opposite leg and the instrument DOES NOT pass thru the setup point (unless you got lucky). 6. Repeat steps 4 and 5. You should notice that each time you do steps 4 and 5, the tripod head will get closer and closer to being roughly over the setup point. Almost always, two to three iterations is all you need to get the tripod head "close enough" so that the legs need not be shifted further. 7. Use your body weight to firmly plant all three legs, exactly as shown in this video 8. Take your plumb bob/gammon reel (if you have one) and hold it under the center of the tripod, and note where the tripod head center is relative to the setup point. Put another way, which way does the tripod head need to go to be over the point? DO NOT look thru the optical plummet at this point. DO NOT use the laser dot at this point if you have one. Those things used at this point will throw you off, because the instrument hasn't been leveled yet. If you don't have a plumb bob, just skip this step. If you do have a plumb bob, move the tripod head closer over the point by slightly shortening and/or lengthening one or two of the legs. This video shows explains that part very well. The goal is to get the tripod head within a tenth of a foot (30mm) of its final location. If you skip this step, you may or may not need to shorten or lengthen a leg during the next step 9. Level the instrument using the three leveling screws, and ONLY THEN look thru the optical plummet. Slide the instrument across the tripod head so that it is directly over the point. (or shorten/lengthen legs and then do that) 10. Check that you are still level after shifting the instrument position on the tripod. If not level, repeat step 9. 11. Rotate the optical plummet to the opposite side of the instrument, recheck the level bubbles and then the optical plummet. Problems then? Your instrument is out of adjustment. Everything checks? Your setup is done. IMPORTANT NOTE: One advantage of this system is the time saved by not having to constantly keep the tripod head approximately level so that you can kinda sorta rely on the optical plummet or laser. I only need to keep the head level enough so that the instrument can eventually be leveled. This procedure is really hard to explain in text form, but easy to teach in person. It is VERY fast, even on a slope or when setting up over a "tall point" (something like a nail in a tallish tree stump). Why did I bother to type this up? I get very frustrated watching people set up using optical plummets or laser dots that aren't plumb, and taking five or six minutes to set up a total station. Finally, it took me a very long time to type this, but this procedure is very fast. It makes a huge difference if you have a lot of setups, and doesn't matter if you set up very few times per day. I hope someone finds this rant useful......
@@johnwetzel5248 Just to clarify, shortening and lengthening the legs changes the position of the plummet over the point VERY mildly. What moves it the most drastically is adjusting the 3 set screws on the tribrach. For that reason, in my own opinion, also humble, is the plummet is way faster and is one movement versus eyeballing plumb several times from multiple angles and then busting out a plumb bob to hang from 5’ high. BUT.. what are “LEAN” concepts anyway. Consistent improvement, updating methods when better ones are present, streamlining systems. If you personally are lightening fast through process practice and you’re examining wasted movement so that you can eliminate it- I’m buying what you’re selling all day long! Side note: if you rotate your total station 90 degrees and the plummet has moved its position it’s time to go get it calibrated. A bad plummet IS a time waster. Tell the repair technician the exact issue by the way, not all technicians are created equal and not all review/adjust the plummet in a standard calibration. Thanks for sharing John. Good data.
@@leansurvey8212 thanks for your comment! My main reason for typing all that stuff is that almost everyone uses some variation of the method you describe, in which a key element includes looking thru an optical plummet that is not completely plumb, but also involves trying to hold two legs in the air while looking thru the plummet AND while trying to keep the tripod head (and instrument) as close to plumb as possible, but without looking at any bubbles because you are looking thru the plummet. And, almost universally, that element of the procedure takes time and (to me) seems fiddly. It is trying to do three things well at the same time! However, in most situations and for most people, it doesn't matter if the setup takes five minutes. I would also say that once I use my method to get close enough to plant the legs, any remaining adjustments can be made by adjusting the lengths of the individual legs even if the tripod head needs to move a lot (let's say two tenths, which almost never happens to me becuz experience!). I think when you are talking about those adjustments moving the point "mildly", that is just what appears to be happening, because shorting or lengthening a leg while looking thru an unplumbed plummet shows little movement, even though the head has actually moved a lot. Then, of course adjusting the leveling screws moves the plummet ring/crosshairs a lot, because you weren't actually as close to the point as the unplumb plummet told you you were. In my method, after I shorten or lengthen legs to get "plumb bob close", I don't look thru the plummet. Instead I level the gun, and THEN look thru the now truly plumb plummet. I am always within two or three hundredths, and I am always close enough to slide the gun over the point. Finally, you spoke of rotating your plummet 90 degrees. The advantage of rotating it 180 degrees is that it shows the full/maximum error. If you are on the point, and rotate 180 and you are two hundredths off, your plummet is one hundredth off exactly. If you rotate 90 degrees as you suggest, you can tell something is off, but you don't know the full amount of the error. Knowing the full error allows you to correct your optical plummet in the field. From the 180 position, you adjust the plummet so that the ring (or crosshair) moves halfway back to what you saw at zero degrees. You might have to do this twice to get the plummet perfect, but you don't need a repair tech. All that said, I want to thank you for taking the time to make your excellent videos and trying to improve everyone's "skills" toolbox. You are a great instructor, and also understand how to make good instructional videos. If folks reading this try my method, they will find that it is not just quick, but less stressful, because the only time you look thru the plummet is when you are almost done, and you are always only a couple of hundredths off, within sliding distance, the gun being already leveled. I just realized as I typed this, exactly why I like my method. It turns out that I am only looking thru my plummet when all three legs are planted and at their final length. So I never need to do the "hold two legs off the ground while looking thru the plummet while also keeping the tripod top level enough then lower the legs while not moving the tripod head" dance. That is the thing I see that looks awkward and inefficient to me, that "dance". That dance also encourages those narrow unstable setups, which I see everywhere.
@@wsyler9922 thanks for mentioning that one. I created a “low budget” video for field engineers and surveyors for in-person trainings a while back- I need to get started on one for this channel that is detailed enough to really communicate the process.
@@leansurvey8212 no troubles. I have a Trimble total robotic station. I’m looking at error adjustment for Arc Second Deviation. I’m not sure how often this is taken into consideration with surveyors as a normal practice. I haven’t seen anything at all about it, not one mention of it really. I guess with GNSS there is really no need for it anymore.
Just a quick question, what exactly is the meaning of "accuracy" on a theodolite manual. To be specific the Futtura Dt10 states accuracy 20" 10" it was written exactly like that with a couple of spaces between 20 and 10.. thats mostly feet they are referring to right?
a short answer here however is that each reading has up to 20” of a degree of variance- so if you turn or observe an angle of 90-00-00, you might actually be looking at 90-00-20 or 89-59-40. You don’t know which, and you don’t even know if it’s the full 20 seconds.. you just know the instrument only warrants its accuracy to that level. At 100’, being off 20 seconds is about 0.01’ of error. At 200’ its double that error, at 300’ its triple, and so on. In other words, they know the construction of the theodolite isn’t perfect, but its at least better that 20 seconds perfect. Make sense?
