good evening ,
i would like know that how the temperature can have an effect on a total station.
i am working in west africa, here in temperature will change every 5 days.
that's why i am wondering how i can set my temperature settings in leica total station.
how temperature effect all measurements.
can i work with default leica settings, or should I change them?
plz reply me.
Replies
all this info is good,but the direct rays of the sun will heat one side until midday, causing the gun to be hot on one side and cooler on the other. a good umbrella in hot weather will work wonders, this will help the gun stay cooler and level and reduce the instrument from crawling off line when a long line is being projected.this also help when turning angles.the only problem with a umbrella is high wind and the boss thinks you want to work in the shade.
Hi everyone, I was just trying to bring out that there is a lot more at play here other than temperature and pressure. Like i mention direct sun rays will heat things hotter than the air temperature. This will cause contraction and expansion in more than in the metals, can be affected by this . Even the level bubbles will contract and expand. other things like heat waves rising off the ground will affect how the edm will measure a dist. also they will affect your line of site on how accurate you can measure your angles. Early in the day is always best to turn your angles even in cold temp. It would best serve the industry if new total sta. could take and calibrate there on temp and pressure setting or ask when turn on to be set before you could continue. This would make sure they were set. and umbrellas, when they can be used, will even come in handy on a rainy day. I am sure that a lot you are aware of this i just wanted to bring it out,to cover all the bases. And old surveyors never die they just lose there bearings.
billy b.
You are awesome Billy!
You have to change the temperature. if it changes in large values
Temp and pressure affect the air density, this affects the velocity of the measuring signal and therefore gives increasing wrong lengths as the temp and pressure move away from their standard value as highlighted previously. Temperature will also affect the internal stability of the instrument as mentioned earlier, so at extreme temperatures 10 degrees about the standard, allow the instrument's temperature to equalise with the surrounding ambient temperature. Another major issue in West Africa is that the instrument expands slightly when hot, and the seals are not so effective in keeping out moisture (particularly a problem in areas of high humidity (Niger Delta etc.), so make sure the instrument is dried out fully before storing. If instrument is left with moisture inside then mildew will grow internally affecting the optics and the electronics. Then the instruments need stripping down and cleaning carefully.
Dear sir, I also agree with this, but I want to know what is happening to the EDM waves due to temperature. I need brief information
I agree with Chris,
as my previous experienced in Qatar 2006 it took me a 3 days to realized how an atmospheric pressure affects during measurement observation specially in an uneven terrain.
During traversing I prefer to input the average/mean temperature rather than the current temperature, try also to consider the atmospheric pressure in your local area. the longer the distance to be measured the greater the error.
I depends on what you want to measure. The temperature matters for ppm setting very much! But these are with differences between for example +15 to 0 celsius. With 40deg celsius you surely have to change the temperature in instrument. Plus it's good to think what you'll be measuring. For example if yoy'll stand in one place with one position by the sun most of the time, it's good to set the instrument up facing the area which you'll be measuring and leave it for 15-25mins to heat up the whole tripod and the instrument. Than correct it and centre again. Most of newer instruments (even old leicas) have 2axis compensator, but still - if you take the instrument from the box, set up and start working you'll see 1h later a disaster. I like to be sure, that I've done all that I can before work. Cheers!
For Total Stations temperature, pressure, and humidity all effect the accuracy of the EDM because they influence the return value of the signal. These are set using a local observation of the various values. Culmination and compensation are internal adjustments to the sensor measurements within the total station.
For general work:
The temperature, pressure, and humidity settings only need changing when there are obvious changes in the conditions; cold mornings/hot afternoons, incoming storm fronts, fog moving in, etc.
Culmination and compensation should be adjusted generally at least monthly and anytime the instrument is subject to something that might alter it; transportation, exposure to conditions outside its published parameters, any kind of physical shock, etc.
Additionally, I have always sent my instruments in once a year for calibration and adjustment. Though I understand that in certain locals this just isn't practical.