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Lighted bar code leveling rods
Posted by john-hamilton on November 21, 2017 at 7:09 pmWe do leveling indoors (tunnels) a few times a year. Sight lengths are not long (about 30 meters max), and a LED “stick” light works well, no problem with the level reading the rod.
Now we have an outdoor project that must be done between midnight and 5 AM, 3.6 miles along a highway (which will be closed). I am wondering how well the LED light might work at the longer sight lengths, like 50 to 60 meters. Another option would be have a person in a vehicle shining the headlights on the rod (highway will be closed down), or maybe using a high power spotlight from the vehicle.
A third option is to get an illuminated rod, but they are not cheap (~$1800), although they would be useful on our monitoring projects in the tunnels.
https://www.tigersupplies.com/Products/Nedo-LumiScale-Self-Illuminating-Leveling-Rod__NED340220-185__NED34022X-185.aspxbrad-ott replied 6 years, 4 months ago 13 Members · 20 Replies- 20 Replies
John Hamilton, post: 456745, member: 640 wrote: We do leveling indoors (tunnels) a few times a year. Sight lengths are not long (about 30 meters max), and a LED “stick” light works well, no problem with the level reading the rod.
Now we have an outdoor project that must be done between midnight and 5 AM, 3.6 miles along a highway (which will be closed). I am wondering how well the LED light might work at the longer sight lengths, like 50 to 60 meters. Another option would be have a person in a vehicle shining the headlights on the rod (highway will be closed down), or maybe using a high power spotlight from the vehicle.
A third option is to get an illuminated rod, but they are not cheap (~$1800), although they would be useful on our monitoring projects in the tunnels.
https://www.tigersupplies.com/Products/Nedo-LumiScale-Self-Illuminating-Leveling-Rod__NED340220-185__NED34022X-185.aspxI just ran into same problem. Running Topcon DL-502 inside a building under construction. Had to use head lamps to illuminate bar code rod. Sometimes not enough light, other times too much light.
I’ve always wondered if the bar code rods are universal. The LumiScale is available with barcode graduations for all popular digital levels. The Leica DNA, Leica-Sprinter, Sokkia, Topcon RAB, and Trimble levels are all represented. Please choose the appropriate barcode rod from the drop-down menu on the upper right-hand corner of the page. The bar code is printed on polyester film (?ñTH < 18 ppm/?øC).The batteries give you approximately 5.5 hours of working time.
It’s been a long time ago, but I remember just having a flashlight in hand shining the face of the rod worked surprising well. You can try that at home after dark to see if that will work.
The patterns are all different, but Nedo makes all of the bar code rods for the various manufacturers (I believe). I don’t know of any other manufacturer of bar code rods. After thinking about it, I think it would be a good purchase for the types of work we do.
John,
Leica use to manufacture a lamp system for the level rods. It was not cheap but it worked. I would think you could do the same thing now days with LED but it might actually be cheaper to fork over the $1800. Than is unless you ever need to use your invar rods in the dark.Interesting that they say the accuracy is between a standard rod and an invar rod.
We ran into a similar situation and ended up getting a Milwaukee M18 Rover flood light, it is pretty bright but we haven’t tested it yet.
The NEDO rods work well and are durable. I have used them for monitoring at the surface and control underground. The light up dummy bubble on the back is a nice touch.
In the long run, the $1800, would be a good investment.
I had done all the setup for a leveling project for an airport, which was closed at night for us.
I made a mount for a high intensity LED flashlight to be mounted on the base of the rod shining upwards.
It worked well for both the Leica digital construction level and the Trimble Dini.I ended up attaching LED headlamps to my rod for use in the tunnel ( one at the top and one at the bottom) – I used two T squares and bent the ends, so the light would shine up and down the rod (the lamps are off to the side out of the rod area ) – Easy and cheap DIY and removable too
They are steady and provide good coverage – I tried the hand held method first – Headlights might work too – 4 lights could be used too
I have also thought that the LED strip lights might work on the side ( attached a strip of z channel to stick them on), just add a lithium battery
Ross,
Your desk looks a little like mine.Looks good. No problems with uniformity of illumination?
The picture is a lot easier to look at upside down in my photo program.
And it’s been a while since I saw that much of my desk surface. Tidiness takes time that could be spent on other work or activities. So long as it’s still an organized mess, there’s no need to clean up. Unfortunately, I’m on the threshold of losing the orderliness.
.We did leveling along a work zone on an interstate at night once and towed a construction light tower, wouldn’t work in a tunnel, but works very well along a road. Under $500/week for rental from a rental yard.
SHG
Got the rod. Went to the job last weekend, it was postponed for a week at the last minute (10 PM, we were supposed to be at a safety meeting at 11 PM) due to snow. Not directly because of the snow, but because the Turnpike maintenance crews that were needed to shut down the highway were busy plowing snow. And that was a 5 hour drive each way. For three people. So they are doing it tonight, but WITHOUT the rod.
Here is what happened…On tuesday we we working on a dam deformation project that we do 6 times a year. We use a 2 meter invar rod for most of it (the dam and inside a tunnel, which had a ceiling too low for the new rod). The last thing we do there is to do a run up a hill from the dam to an off structure control station. We use a 4 m folding rod (wooden) for this, which has proved to be very good. Excellent results over the years. But, due to snow squalls it was getting dark by the time we got to that. So, we used the new rod. It is about 150 meters each way, with a difference in elevation of 14 meters. So, numerous shots high on the rod followed by low on the rod shots. Closed good, 0.0001 meters (1/10th of a millimeter). But, the run disagreed with previous runs by 20 mm. That is a big deal, did the dam (huge concrete structure that is 80 years old) settle? Or did the monument off structure move?
So, I first checked our GPS, we have two GPS stations on the dam (high up on tower roofs), and three off structure that we observe each survey.
These are raw differences in elevation, all in meters for the 5 surveys we have done in 2017 (one more to do the last week of december)…ASE2 is the station that is located off the structure, about 14 meters higher than the dam, EAST and WEST are on the dam (on top of tower roofs), PLANT2 and BOATRAMP are upstream/downstream…M01R is also on the dam, it is the station we level to each survey from the off structure station.
From To #5 #4 #3 #2 #1 BOATRAMP ASE2 38.354 38.344 38.351 38.353 38.343 GPS WEST ASE2 3.786 3.785 3.788 3.779 3.778 GPS EAST ASE2 3.791 3.791 3.801 3.790 3.792 GPS PLANT2 ASE2 69.114 69.116 69.114 69.112 69.115 GPS ASE2 M01R -14.4283 -14.4088 -14.4088 -14.4101 -14.4085 Levels Here is a picture looking from station WEST to EAST, ASE2 is behind the pine trees in the background, on the spillway axis extended.
So why the discrepancy? It appears from the GPS data that all is stable. We also have total station data verifying that.
Next, we tested the rod at several heights against a 2 meter invar rod. At each of three we shot both rods. Any difference should be consistent.
invar lighted Difference 1.68500 1.68609 -0.00109 0.96361 0.96447 -0.00086 0.46338 0.46381 -0.00043 The above values are in meters. I should have used a 3 meter invar and shot higher, as the highest reading on the illuminated rod was about 2.1 meters. I imagine the error higher up on the rod is even greater. But, in any case, it clearly shows a scale problem on that rod. I was shocked. Nedo claims this rod is between a regular rod and an invar rod for accuracy. Because we had the same number of high on the rod/low on the rod shots going up hill and back down, the errors all cancelled and the loop closure was very good (0.1 mm). But, overall there was 20 mm of error in the run.
So, we are out tonight using a regular rod and LED light bar. And sending that piece of !@#% rod back.
Nice work John. Testing “NEW” equipment as you did (while verifying your results), is the sign of a true Professional.
Loyal
like?
I should have tested it before, but we were not expecting to use it on that project, only needed it because the snow squalls put us behind schedule.
Yes, I like the design of the rod, but it is totally useless to me with the scale problem.
Thanks for the info report John, I thinking about getting one to replace my 15 year old fiberglass rod. Let us know how the manufacture responds.
So it occurred to me that maybe the difference was a linear function, and that I could correct the rod readings. Here is what the three data points look like, they certainly look linear…
So, if I apply that scale factor (1.0005) to the data, it only changes it by 7 mm. The constant part does not matter, it cancels out with BS/FS.
That does not account for the full 20 mm of difference I am seeing. I am going to get more data points , especially near the top and bottom of the rod, see if that changes anything.
I, for one, do appreciate you “thinking out loud” here. I am enjoying watching this thread without having to “think” myself. Sometimes it takes days of chewing on a problem like this before a solution presents itself.
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