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Mixed units

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(@loyal)
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I've been watching the comments about "units" with some amusement.

In my work over the years (virtually all of it in retracement mode), mixed units are a fact of life.

PLSS/Section-Township-Range:

Courses in Chains & Links, but Monuments in Inches, and Bearing Trees/Rocks/Objects/etc. in Inches, (distance to them in Links).

Mineral Surveys:

Courses in Feet and Tenths (sometimes hundredths) of a foot, but Monuments in Inches, and Bearing Trees/Rocks/Objects/etc. in Inches, (distance to them in Feet and Tenths/hundredths).

All of my "other work" is geodetic in METERS, until I convert the results to Ift, USft, or sometimes just leave it in Meters depending on client.

Loyal

 
Posted : 14/08/2019 10:46 am
(@gene-kooper)
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It is amazing that you never get confused working with all those different units, Loyal!

 
Posted : 14/08/2019 11:06 am
(@loyal)
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Posted by: @gene-kooper

It is amazing that you never get confused working with all those different units, Loyal!

Yeah...it's tough, but I manage.

????

 
Posted : 14/08/2019 11:31 am
(@scott-ellis)
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You forgot the greatest unit of measurement, the Vara.

 
Posted : 14/08/2019 12:44 pm
(@bill93)
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He probably didn't forget the vara. He was just listing the ones he uses.

 
Posted : 14/08/2019 1:17 pm
(@norm-larson)
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Loyal, I'm with on all that you mentioned except mineral surveys, but, I can add mm and cm for 3D printing.?ÿ and then there are the unofficial nudges, hairs, bits and skooshes.

 
Posted : 14/08/2019 2:38 pm
(@dallas-morlan)
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Several years ago a similar thread involved a discussion of "Smoots" as a unit of measure.?ÿ?ÿ I suggest we not go there again. However, now that I've mentioned it I'm sure someone will journey down that rabbit hole.

 
Posted : 14/08/2019 3:13 pm
(@am95405)
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Maybe you can give our local DOT people (Caltrans) some lessons.

Miscalculation shuts down College Avenue widening

This was in 2014. College Avenue is near the Community College :-), where there are courses in surveying and civil engineering.

"A major design error has halted the $6.7 million Caltrans project to widen College Avenue under Highway 101. ƒ?? Engineers miscalculated the elevation of the new roadway by up to two feet, failing to properly account for the slope of the driveways leading to businesses along the north side of West College Avenue. ...?ÿHe suggested a conversion error from metric units to English units may have been to blame. "

To me, one of the issues with conversions is "having a gut feel" for the numbers. I grew up with metric (K-12) and then came to the States and learned the imperial system. I used to have a good sense of what 2 km or?ÿ2 hectares meant. It took me years to develop that same feeling for?ÿmiles or acres. The point of the gut-feel is so you have some idea if your calculations or measurements are really wrong. I've seen that in our community college where I take classes, where students (in surveying) come up with answers for problems that are completely off. I think it's a valuable skill to have some idea of the measurement value, before you've even made a single measurement. And having a sense for the units really helps that.

 
Posted : 14/08/2019 3:44 pm
(@dougie)
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Posted by: @loyal

In my work over the years (virtually all of it in retracement mode), mixed units are a fact of life.

I'm not sure it matters, what "mode" you're in; mixed units are always, a fact of life, when you're a surveyor...

 
Posted : 14/08/2019 4:07 pm
(@loyal)
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Posted by: @dougie
Posted by: @loyal

In my work over the years (virtually all of it in retracement mode), mixed units are a fact of life.

I'm not sure it matters, what "mode" you're in; mixed units are always, a fact of life, when you're a surveyor...

I agree Radar, I was only stating that I DON'T do construction, residential, urban, suburban, lot splits, etc., and I still see mixed units in the "official" GLO/BLM records that I DO deal with.

????

 
Posted : 14/08/2019 6:56 pm
(@dougie)
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@loyal

Yup, just another day in the life...

 
Posted : 15/08/2019 5:42 am
(@dave-karoly)
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@dougie

All the cool kids have a pocket tape which reads in FEET and METERS.

 
Posted : 15/08/2019 6:57 am
(@dougie)
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@dave-karoly

I even heard,  once, that you need to use a "special" tape,  if you want to make measurements in Manhattan ????

 
Posted : 15/08/2019 7:42 am
(@bill93)
Posts: 9834
 

Wouldn't surprise me about Manhattan.  In Philadelphia we were told that the old part of the city was laid out with a different standard for the foot, the difference easily seen on a 100 ft tape, and in the 20th century you could order a Philadelphia tape made with that standard.

 

 
Posted : 15/08/2019 8:41 am
(@jimcox)
Posts: 1951
 

@dave-karoly

These double measure tapes are getting darned hard to find here in MetricWorld.

NZ never used feet for surveying - our old work was  done in chains & links, but the tapes are very useful if you are maintaining an old home built in imperial measure.

 
Posted : 15/08/2019 9:57 am
(@a-harris)
Posts: 8761
 

@jimcox

It has always been that we have to go to a survey supply to get a tape in feet and tenths.

They are rarely kept in any of the local or nationwide supply stores.

Even then if they are in supply, it has feet and inches or metric units on the other side of the tape.

 
Posted : 15/08/2019 12:13 pm
 Norm
(@norm)
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Posted by: @loyal

I've been watching the comments about "units" with some amusement.

In my work over the years (virtually all of it in retracement mode), mixed units are a fact of life.

PLSS/Section-Township-Range:

Courses in Chains & Links, but Monuments in Inches, and Bearing Trees/Rocks/Objects/etc. in Inches, (distance to them in Links).

Mineral Surveys:

Courses in Feet and Tenths (sometimes hundredths) of a foot, but Monuments in Inches, and Bearing Trees/Rocks/Objects/etc. in Inches, (distance to them in Feet and Tenths/hundredths).

All of my "other work" is geodetic in METERS, until I convert the results to Ift, USft, or sometimes just leave it in Meters depending on client.

Loyal

Not to mention the RCH. Remember I didn't mention it.?ÿ

 
Posted : 15/08/2019 12:32 pm
(@scott-ellis)
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@a-harris

Lowes carries the 100, 200, and 300 feet, but like you said in inches, and tenths, which is just a problem waiting to happen. 

 
Posted : 15/08/2019 1:18 pm
(@a-harris)
Posts: 8761
 

@linebender

"30 microns. Measured on a comparator by a physical scientist on his secretary's RCH at the Defense Mapping Agency'sErskine Hall, Bethesda, MD sometime around 1980" 

 
Posted : 15/08/2019 1:47 pm
(@dougie)
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We had a tape, once, that had an extra foot. It seems that it got hung up in the machine and the same foot was stamped twice...

So my point is; you can measure anything, with anything, and the bottom line is, you need to prorate your results.

 
Posted : 15/08/2019 4:07 pm
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