A three section, 15 foot prism pole is sometimes really handy. Our old one was really beat up and we got a new one. This new Seco is dual graduated in meters and feet which is fine; there are meters to ignore. What is not so fine is that it is PRIMARILY in meters, which is to say that the three section increments are exactly 1.65m, 2.65m, 3.65m, and 4.65m or ~5.41ft, ~8.69ft, ~11.98ft, and ~15.26ft.?ÿ I was unable to find a three section prism pole graduated primarily in feet.?ÿ Does anyone know if these are available and where to find them??ÿ Our old rod heights were 5.3ft, 8.4ft, 12.0ft, and 15.5ft.?ÿ
Without a pole with more desirable, primarily feet graduation marks, what approach do people use with poles that are primarily metric??ÿ We could memorize those rounded numbers and use them.?ÿ We could enter the rod height in the fieldbook and equipment in meters and let the computers convert it.?ÿ This would look odd in the fieldbook since everything else is otherwise in feet and tenths.?ÿ We could keep using our old pole which is in poor condition and not repairable.?ÿ
Thoughts or ideas?
Thanks, Eli
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You already answered your question: "We could memorize those rounded numbers and use them."
You could do what we have done when we need poles of a particular length - ask a local engineering works to make some. Specify aluminium tube and brass insets for the threaded ends. Over the years we have had a couple of dozen made to various lengths and diameters.
Most firms have some down time each month and this is the sort of job that they can use to fill in the spare moments - when you make the enquiry explain that there isn't a rush - you need them within a month or so - and they will price accordingly. Once they have done business you will be surprised at how many "gadgets" you might ask them to make to ease things along on site.
It's probably worth getting them powder coated, if there is a firm near you who does that. Then you can get them striped in feet. Or you can just paint them yourselves - but make sure you use a good metal primer first.
We use metric in all field work. It can be hard to find tools (measuring tapes, rods, etc) graduated only in meters. So I have the opposite problem.?ÿ?ÿ
You already answered your question: "We could memorize those rounded numbers and use them."
My lack of enthusiasm for that comes from the "rounded" part.?ÿ
Just use metric.?ÿ Whit most DCs switching between US feet / Meters / Int Feet is just a button push away. ?ÿ Like John, I use metric for just about everything and then convert to the desired flavor of feet when required.?ÿ It solves a lot of issues working in multiple states using different foot definitions.
You already answered your question: "We could memorize those rounded numbers and use them."
My lack of enthusiasm for that comes from the "rounded" part.?ÿ
What are you measuring with an adjustable rod that needs to be more accurate than a 0.01'??ÿ You could always memorize them to the thousandth.
You could do what we have done when we need poles of a particular length - ask a local engineering works to make some. Specify aluminium tube and brass insets for the threaded ends. Over the years we have had a couple of dozen made to various lengths and diameters.
Most firms have some down time each month and this is the sort of job that they can use to fill in the spare moments - when you make the enquiry explain that there isn't a rush - you need them within a month or so - and they will price accordingly. Once they have done business you will be surprised at how many "gadgets" you might ask them to make to ease things along on site.
It's probably worth getting them powder coated, if there is a firm near you who does that. Then you can get them striped in feet. Or you can just paint them yourselves - but make sure you use a good metal primer first.
Chris, by adding length to the pole you are making all of the measurements read incorrectly.
Most every modern prisim pole has an adjustable prism bolt.
Basically it takes a thin nut to adjust to whatever height is required.
Some of our poles have stops. You could get them installed or install them yourself, they work really well and you can chose the height, that way you don't have to worry about slips.
Are the graduations on the pole even correct to the center of the prism? Yes, most poles now are adjustable, but I'm not a fan of that, even if there's a lock washer on it. I'm assuming that, like Trimble Access, any data collector now will convert meters to feet if the units are set to feet and you make the entry in meters - in other words, enter "2m" in the height field and when you hit Enter it changes to 6.562. If the height can be read in meters enter it in then write the converted number in the field book.
Like John and John, I use meters for a lot of things; the millimeter is a smaller unit of measure than the hundredth and I need accurate HI and HT values when scanning with the SX10. Trimble's traverse kits have these nifty little arms that you can measure the HT to and when you put it in Access it corrects it for the slope.
Ever since Seco was purchased by Trimble, I have heard and had nothing but bad things.?ÿ
tribrac's are shipped without being properly aligned. Prism poles being primarly metric. And the biggest problem, products being unavailable.
Seco shipped product that wasn't calibrated and in some cases not properly assembled long before they were acquired by Trimble. Any dealer worth doing business with checks that stuff so end users don't necessarily see it.
Chris, by adding length to the pole you are making all of the measurements read incorrectly.
John,
A misunderstanding somewhere. You just add the length of the extension pole to the length you have set on the main pole and record that as the target height. Or does your pole automatically record what it thinks is the length?
Are the graduations on the pole even correct to the center of the prism?
Don't forget that the points wear down - for accurate heighting you need (a proper level!!) to check the length of the pole and replace the point when necessary - and, as Lee says, check the locking position on the pole frequently during the job.
When we need to use the EDM for accurate heights we often just use the extension rods with a point screwed in - that way they cannot slip.
Chris,
I think the OP was concerned about the actual marking on the pole being in metric at the end of each extension?ÿ not adjusting for the prisms vertical offset.
Don't forget that the points wear down...
Noting that height for each pole is important.?ÿ I noticed some OPUS Share submissions where someone remeasured marks that also had ellipsoidal heights measured by NGS (not published yet but available in other NGS documents).?ÿ Their measurements with a black pole pictured were consistently about 0.1 ft lower than NGS and the green pole 0.1 ft high.?ÿ Apparently someone mixed up which pole was which.
You could do what we have done when we need poles of a particular length - ask a local engineering works to make some. Specify aluminium tube and brass insets for the threaded ends. Over the years we have had a couple of dozen made to various lengths and diameters.
Most firms have some down time each month and this is the sort of job that they can use to fill in the spare moments - when you make the enquiry explain that there isn't a rush - you need them within a month or so - and they will price accordingly. Once they have done business you will be surprised at how many "gadgets" you might ask them to make to ease things along on site.
It's probably worth getting them powder coated, if there is a firm near you who does that. Then you can get them striped in feet. Or you can just paint them yourselves - but make sure you use a good metal primer first.
That's what I did about 10 years ago in Az. then a few years later here in Baja. I could not get them quick, but the machine shop had them done in a day or so. First poles were aluminum, second sets were stainless steel...bronze fittings. It was actually much less expensive. All I did was provide a sample, I got exact copies.
I painted the candy stripe myself, but if I had time powder coat would probably be more durable.