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Choosing the Right Instrument

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field-dog
(@field-dog)
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Topic starter
 

This morningƒ??s meeting included purchasing new equipment. Yes! What is the recommended precision (5ƒ?, 3ƒ?, 2ƒ?, etc.) for an instrument to perform boundary surveys? We may not have to stay with Topcon.

 
Posted : May 31, 2023 6:18 am
rover83
(@rover83)
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Boundary surveys? No high-precision work (monitoring or control networks)? Any of those will do just fine.

Depending on what your typical standards are you might need to adjust your SOP to add or remove observations while observing sets of angles.

There's usually a pretty good price jump somewhere between 3" and 1", so if all you're going to be doing is boundary, it might make sense to go with 3" and put that extra money into something else. Training, accessories.

 

We may not have to stay with Topcon.

Good. Test out other brands - and also test the dealers pushing them.

 
Posted : May 31, 2023 6:46 am
(@lurker)
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Anything less than 3" is spending money with no appreciable benefit.

 
Posted : May 31, 2023 7:49 am
Norman_Oklahoma
(@norman-oklahoma)
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Posted by: @field-dog
We may not have to stay with Topcon.

 

I've written here about my disdain for the Topcons I've been forced to use for the last several years. I'm counting the days to the next fiscal year when I will have budget to purchase a new Leica. Some people are Topcon people  - I can't figure out why. Test the Trimble and Leica against the Topcon at your peril. If you are forced to use Topcon after getting a taste of what a good instrument can do you will never be happy (at work) again. Not about the performance of your instrument, anyway.

As for 1" vs. 3" vs. 5" ...... If you put a pristine 1" instrument on top of the average tripod and tribrach and aim at the average prism glass, all selected at random from the average truck's kit, and deploy it in the common way, you will be lucky to get 10" results. Do the same with a 3" gun and you will probably get practically the same. So unless you are prepared to also upgrade those accessories,  keep them in pristine repair, and, very likely, amend your field procedures, don't bother with the 1" instrument.  Unless the difference in cost is very slight.   

 
Posted : May 31, 2023 8:02 am
(@bstrand)
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Yeah, I'm not a fan of Topcon either.  I'd suggest Trimble but you know you're gonna throw away money on the name if you go that route.  I'd probably pick Carlson over Topcon actually if I was gonna stay in that price range.

 
Posted : May 31, 2023 8:23 am

Norman_Oklahoma
(@norman-oklahoma)
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I'd probably pick Carlson ....

Which, like Geomax, is a rebrand of Leica. Good choice, IMO.

 
Posted : May 31, 2023 8:28 am
field-dog
(@field-dog)
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Topic starter
 

No high-precision work (monitoring or control networks)?

No.

 

 
Posted : May 31, 2023 8:42 am
oldpacer
(@oldpacer)
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OPINION - high, medium, low
Topcon – medium price, medium endurance, medium quality
Leica – high price, high endurance, medium quality
Trimble - high price, medium endurance, high quality
Geomax - low price, medium endurance, medium quality
Trimble if you have all Trimble equipment and a global field process. Geomax if standalone with no fancy 2020 technology. Carlson is making a run if you have all Carlson, but they have no history, could give up tomorrow. If you yourself, run and maintain, Topcon ok. If field crews runs it, Leica or Trimble. All around for me, Leica. ALL plates are made the same, only post manufacturing grade to 5”, 3” or 1”. A 5” gun is fine for traverse for Boundary Surveys. I learned on a 20” gun, closed routinely at 1 to 40. Modern 1” and 3“ guns got me 1 to 50. Go figure. My best advice is find a good dealer you like and can work with and buy his gun. Good Luck.

 
Posted : May 31, 2023 9:31 am
(@mark-mayer)
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Leica being high priced is the long held thinking. But when I bought GPS a couple years ago it was priced comparably to the Topcon, with Trimble being significantly higher.

 
Posted : May 31, 2023 10:42 am
dave-karoly
(@dave-karoly)
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I hardly ever use my total station anymore.

I'm at the point where I go on entire trips without it, it’s just in the way, the box in the truck with the instrument I’m not using.

 
Posted : May 31, 2023 10:46 am

field-dog
(@field-dog)
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Topic starter
 

Anything less than 3" is spending money with no appreciable benefit.

Concerning spending money, we have to justify any equipment that we want to purchase. Other than opinion and brand loyalty, are there any specifications that our engineering department head can look at? In other words, a survey with a required closure of 1:10,000 would need a minimum of a 5” instrument. I remember seeing horizontal control standards published by the NGS. Maybe I should look at Florida’s minimum technical standards.

 
Posted : May 31, 2023 10:49 am
bill93
(@bill93)
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With care and repeated observations a 5" instrument can do much better than that.

 
Posted : May 31, 2023 12:30 pm
(@chris-bouffard)
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1", 2", 3", 5", don't get hung up on that stuff.  These are all theoretical accuracies resulting from bench mounted set ups under controlled conditions in a lab somewhere.  Your precisions and accuracies are all determined by your methods and procedures.

Back in my way younger days I achieved pretty darned tight closures cranking angles on a 30" K & E optical transit while back sighting and fore sighting plum bob strings and gammon reels with chained distances.  Again, it's all about methods and procedures.

You will be hard pressed to explain the want or need to purchase equipment of quality to an Engineer who has not spent significant time surveying.  They won't understand what you are telling them and will more than likely base any decisions on spreadsheet profit goals.

I have used exclusively Leica equipment for the past 13 years for a number of reasons including the relationship I have with my Leica Rep and the optics that no other manufacturers can match.  All of my guns are 2" TS 15s with Leica network RTK kits too.  I have a mix of TS 16 total stations and robots and I'm running 6 crews with two reserve kits to accommodate rotating servicing and needed repairs.

I'm in a unique position where my CEO hired me to establish a survey department for him.  He is neither a surveyor or engineer and gives me full authority to run my department the way that I want to.  Whenever I want or need something, I tell him and explain why.  In 8 years he has never denied or questioned my purchase requests.

 

 
Posted : May 31, 2023 12:46 pm