Hi guys
I've been surveying for just over a year now and have always found other jobs to do when its raining - like internal measured surveys or office work.
Today its raining and I have to get this topographical survey done. The rain doesn't bother me I have decent waterproofs.
But will it affect reflectorless shots - the laser could hit a rain drop and return?
Can it affect 360 prism shots? Do I need to wipe down the prisms periodically?
Please give tips for working and the rain and still doing accurate work.
Cheers, Andrew
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forgot to mention - I work by myself
I've been using robotics since the GDM4400 was first produced and never found any accuracy problems.
What you will get is a somewhat reduced range if too many rain drops collect, but if you plan your work to keep, say, within 70% of your maximum normal working distance then this shouldn't be a problem. Any drop of accuracy is likely to be far less than your ability to hold the pole vertical (perhaps an mm. or so??)
You will give up long before the rain is too heavy to make the instrument hand its notice in.
Enjoy your day!
Have setup the instrument under carport, porch, tarp and umbrella many a time to finish a job.
Jump in and get r done.
From experience, you will on occasion need to wipe off your 360?ø prism and perhaps the backsight glass as well in order to get a return. Chris Mills is correct, you will have reduced range; but usually not an issue if you have adequate control. As far as accuracy goes... I've never had a problem save for an EXTREMELY rare bad return (error in distance), which may have been due to some other factor such as cosmic radiation adversely affecting memory or other circuitry in the gun.
I was not aware that they made water proof robotic total stations.
I was not aware that they made water proof robotic total stations.
I have been told that the total station and GPS units are "water-proof". Weather resistant is the technical term I was given.
They are until they aren't is my interpretation of the quotes. How things get handled from there are for the warranty department to decide.
Generally a lot more weather resistant than the surveyors!
I've never had one fail in the rain (although I've never had one underwater to find out when they do). Once, after a torrential 8 hours of rain we sent a GDM back for checking - there was a VERY slight damp patch which might have caused some risk of corrosion over time.
In the Pacific Northwest we work in the rain routinely. It's really not a problem. If it rains really hard drops can get on the lenses and affect range and tracking somewhat, but that's only in really hard rain. I keep a small hand towel on hand to dab off the drops on those occasions.
At the end of the day towel the thing off thoroughly and set it all out in a heated room to dry overnight. Same for the box and all the accessories. I've done this day on day, year on year and have no problems with moisture.
Seals are frangible. Which means that if you open up the instrument housing you must use new seals when you put it back together. If you don't, you will have moisture problems.?ÿ ?ÿ
Rain drops on the lens/prism affect the ATR and the distance measurements from my experience with Leica TPS 1200 robots. I had 8 to 10mm errors in point location at 30m distance from the instrument. My solution was to use the sun shade on the instrument's lens and wipe clean the prism before each shot. The work I do requires high accuracy (2mm tolerances) and , to be honest, I only work in the rain if the concrete is already on site and the anchor bolts need to be placed right away. I told my employer l?ÿ can't guarantee the required accuracy?ÿ in the rain, or snow. On top of this the TPS 1200 is only rated IP 54.
My biggest problem in the rain is drops actuating the touch screen on the DC. Or, alternately, causing my 'taps' to be interpreted on a different section of the screen.
More of a headache than anything. And, trying to wipe off the screen leads to inadvertent commands being issued (still not a big issue). Someone previously recommended using 'Rain X' on the screen to alleviate this problem. Haven't tried it.
No issues with the robot or prism, in my years. Everything does just fine lying in the back of the truck. ?????ÿ
I tell my guys that all the equipment is more rain proof than us. Expect for the paint.
I was not aware that they made water proof robotic total stations.
Steve,
You're so funny.?ÿ If total stations didn't work in the rain those of us on the west coast from Eureka to Anchorage wouldn't be able to work 2/3rds of the year.?ÿ It rains a lot here.?ÿ
I've never had an instrument fail from?ÿ getting rained on.?ÿ I did have one get fried working under a BPA line in the rain.?ÿ You just have to bring them in and let them dry out every night.?ÿ Leaving a gun in the case is a firing offense at my shop.
As for accuracy, it has to be coming down harder than I want to be in for the gun to act up.?ÿ The biggest problem around here is Oregon mist.?ÿ Think light fog with big droplets.?ÿ ?ÿThe stuff just soaks you and the instrument freaks out trying to track you.?ÿ
I had a total station develop a moisture problem one time that cost me more to have fixed than the gross invoice for the job we were doing when caught in a downpour. ?ÿThat has never happened again, mainly because we now stop surveying when significant rain starts. ?ÿWiping the unit down as well as possible and getting it to a place where it can be air dried to get residual moisture gone is always a smart idea.
That was MY money paying for the repair.
I had a total station develop a moisture problem one time that cost me more to have fixed than the gross invoice for the job we were doing when caught in a downpour. ?ÿThat has never happened again, mainly because we now stop surveying when significant rain starts. ?ÿ
Back in the early days (c.1989) total stations were not so water proof.?ÿ This was probably, at least partly, because of the frangible seals issue I noted above.?ÿ ?ÿ
Nevertheless I don't blame you for not working in the rain in Kansas. PNW rain generally doesn't come with lightning and swirling winds like it does on the prairie. I work in the rain, but not in a tornado.
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