I had the instrument set up to pin some footings. (Had to be done yesterday no matter what). There was a misty rain blowing around kind of sideways. The outside of the tracking mechanism as well as the lens and prism on my TCRP 1203+ robotic setup kept getting coated in condensation. It was extremely annoying as I would lose the ability to track, walk back to the gun, clean it off, reset zero, and attempt to continue staking.
Toward the end of the day when I was wiping down the instrument to put it in the case I noticed that there appeared to be moisture inside the ATR mechanisms where the track lights are above the lens. I got it back to the house and removed the gun from the case and placed it in front a space heater (set to low heat) some distance away. It appears to have removed the moisture.
Has anyone else had this happen?
I've used similar instruments (a couple different 1205 units) in heavier rain with no problem. I guess I have to invest in another 4-legged pop up tent to keep it covered during inclement weather.
dan, i have always been leery of using heat on wet instruments. internal condensation, for lack of a better phrase, might short something. we use a leica robot, and have gotten it wet many times
i generally set gear up in front of a fan overnight.
Dan, every instrument has to be either completely sealed. (Think gas filled) or vented, to work with local pressure changes. That is, such things as local atmospheric pressure changes. Many folks fly these days. And, shipping is by air. So, at 35,000 ft, there is less atmospheric pressure.
So, what they often do, is SEAL the telescope, and fill it with gas. But, other parts, they vent.
The FIRST thing I'd do is to determine if the ATR mechanism is supposed to vent, or be sealed.
If it is supposed to be a sealed unit, with gas in it, send it home to momma. Get it re sealed.
Because your problems will grow, if it is compromised. Just find out. IF it is supposed to be vented, then you will have to develop protocol, to get her dried out. Humidity around he can be high.
Just find out. Somebody knows.
N
That's why I set the temp low. It's a fan type unit and I had the gun several feet away from it. I didn't want to apply direct heat to it. (just didn't seem like a good idea)
> That's why I set the temp low.
As a rule of thumb (so to speak), I figure if the heat is low enough for my hand to withstand without discomfort, then the instrument can handle it, too.
Dan,
On the issue of the instrument losing tracking with the rain on the lens and prism. ATR is basically the same as an instrumentman sighting the prism with the lens coated with water and the prism coated with water. If the instrument operator could not see the target clearly due to rain on the lens then the ATR cannot see it either. The best thing to do is to put the sun shade on the lens to keep water off. The Power Search should not be affected by it.
The ATR is not located on top of the scope. On your TPS1200 Plus model if you are looking directly at the objective lens - the EGL (Electronic Guide Lights) are on the left and the Power Search components are on the right. The small prism-looking component is the transmitter for the Power Search and the larger circle is the receiver for the Power Search. If this is fogged up you probably just have an issue with the seal for the top cover of the telescope housing. The ATR beam is coaxial… it exits and enters the instrument through the line of sight. So the ATR beam comes out of the center of the lens, returns to the instrument in the same area and is monitored by a system in the telescope housing. So it may be that all of the components inside the telescope housing are getting “extra moisture” on them.
This moisture issue should not happen as you have pointed out and I would get the instrument looked at in a Service Center for the condition of the seal. The TPS1200 Plus series first came out in about July 2008. Depending on the manufacturing date the instrument could be 5 to 6 years old and due for some routine maintenance. Again, I agree … you should not have this moisture issue. Service can resolve the issue.
Just a quick advice,
Where I am it rains almost everyday. We would keep out stations and prisms in a dry cabinet at the end of the day to keep any moisture out of them. Dry cabinet would be like those used to store lens. Found them to effectively solve any problem of unclear sights through the plummet too.
It would be wise to inspect your Leica TCRP1203+ carefully, and perhaps take / send it to your local leica service center.
