Zeiss R50 total station - Q
CoPLS
Anybody out there using a R50?
If not, any particular reason why?
Thanks,
Ron
Kent McMillan
>
> Anybody out there using a R50?
> If not, any particular reason why?
Ron:
If you mean the Zeiss Elta 50 (which was/is offered in the 50R version),
I use one. In the interest of disclosure, I should mention that I've
always preferred Zeiss equipment and have never seriously considered
using the instruments of any other manufacturer. Over the years, I've
used the Th43, Th2, RSM3, and the Elta46R. Each was a very nicely put
together instrument that gave (and still give) excellent service in the
field. Having established my bias, now, I'll say that the Elta 50 is a
very good little instrument, especially for the price.
I'd say that Zeiss has possibly underspecified its angular accuracy. I
consistently get better results than the spec. The fineness of the
tangent motion is probably a tad bit coarse, but this is not a fatal
defect.
My only objection to the present line of Zeiss Eltas is one that I
suspect applies equally to all of the other manufacturers. I wish that
the portions of the service manual that pertain to the determination and
storage of EDM constants and horizontal circle constants (the
corrections used by the internal software that are not ordinarily
instrument menu items) were available to those of us who like to tweak
our instruments ourselves rather than having to send them back to
Germany to have it done.
I suppose that the manufacturer judges (correctly) that it is so
possible to greatly reduce an instrument's performance by entering
erroneous calibration values into its memory, that they have decided to
limit access to technical information to prevent this from happening.
Personally, I just prefer to be able to look into black boxes whenever
possible. I've never been quite comfortable with the pervasive all
electronic instruments that rely upon software corrections (such as the
cyclic error and temperature dependent corrections to EDM ranges) but do
not tell the user exactly how the corrections are being applied.
This secretive attitude seems a bit silly to me in that I'd assume that
the manufacturers themselves all know how their competitors' instruments
function. They have no secrets from each other, only from their
customers.
The above minor complaint should not prevent you from seriously
considering the Elta 50. As I said, it is a complaint that most likely
applied to all of the manufacturers. The Elta 50 is a very nice, but
mysterious, little instrument.
Best regards,
Kent McMillan, RPLS
Austin TX
Michael W. Gupton
You didn't pay for it!
I'd sure use one if our budget could afford it!
Mike
CoPLS wrote:
> Anybody out there using a R50?
> If not, any particular reason why?
>
> Thanks,
> Ron
Kent McMillan
>
> I must say I'm surprised that you would need to return the equipment from
> Texas to Germany for this! I can't speak for other manufacturers, but any
> Sokkia service centre which has a collimator and other checking facilities
> can calibrate a Sokkia Total Station and enter the calibration values into
> the Total Station by means of special service software.
>
> This also answers your question on why end-users don't have access to this
> capability: you need a collimator.
>
> Paul Koren
> Sokkia BV, The Netherlands
Paul:
How is the collimator used as other than a well defined target at
infinity focus? The commonest collimator arrangements I'm familiar with
are two 180 degrees apart from the instrument stand, with a third
colimator elevated above one of the first two.
This doesn't strike me as an impossible target arrangement to easily
duplicate using common survey targets. Is not the reason for using
collimators in the first place because most instrument repair facilities
are in confined, indoor spaces?
As for sending the instrument to Germany, yes that is a bit of an
exaggeration. Zeiss does have a number of authorized repair facilities
in the U.S. As quick as international air freight is, though, I'd
rather send an instrument to the experts in Jena than to New York.
Kent McMillan
>
> Zeiss!
> You didn't pay for it!
> I'd sure use one if our budget could afford it!
> Mike
Mike:
Actually, the Elta 50 is surprisingly inexpensive. After years of
making top quality instruments with hefty price tags, Carl Zeiss has
produced a number of nice instruments that are surprisingly easy on the
wallet. The Elta 50 is one of those.
Paul Koren
This is indeed the essence of a collimator, so you could do this in the
field with well-defined far-away targets. But still you would like to check
your vertical encoder too, and your horizontal axis.
Bottom line is -you're right- that we expect more trouble from it than
customer benefit, if we would allow these values to be entered by users. It
is just too easy to mess up.
best regards,
Paul
Diego Berge
Have you tried talking to the tech service guys and asking for the
proper steps/software to adjust those parameters? I don't see no reason
why they shouldn't give it to you, aside from warranty concerns. In any
case, as Paul Koren points out, you'd probably be getting better results
with a collimator and an anti-vibration bench.
Kent McMillan wrote:
>
[ Parts snipped ]
> Best regards,
>
> Kent McMillan, RPLS
> Austin TX
Regards,
Diego Berge.
Kent McMillan
> Have you tried talking to the tech service guys and asking for the
> proper steps/software to adjust those parameters? I don't see no reason
> why they shouldn't give it to you, aside from warranty concerns. In any
> case, as Paul Koren points out, you'd probably be getting better > results
> with a collimator and an anti-vibration bench.
I have posed the question to various people connected with the
manufacturer. I didn't see any reason either why what are essentially
routine service procedures should be so difficult to get instructions
for.
The broader problem that strikes me is the following: just how well we
surveyors should like using black box instruments? By "black box", I
mean of course a device that outputs measurements that have been
produced by a process that the manufacturer declines to discuss in any
great detail. One could make an argument either way, but personally I
prefer more explanation rather than less.
On another line, I'd question whether the average survey instrument
facility is equipped to do EDM calibrations any better than many
surveyors can. I certainly doubt that most facilities do much better
than possibly testing the instrument at close ranges on a linearity rail
supplemented by a couple of longer measurements to verify function.
Skeptically,
Diego Berge
>
>
> I have posed the question to various people connected with the
> manufacturer. I didn't see any reason either why what are essentially
> routine service procedures should be so difficult to get instructions
> for.
>
> The broader problem that strikes me is the following: just how well we
> surveyors should like using black box instruments? By "black box", I
> mean of course a device that outputs measurements that have been
> produced by a process that the manufacturer declines to discuss in any
> great detail. One could make an argument either way, but personally I
> prefer more explanation rather than less.
I agree, besides, you can always ignore what you think you don't need
to know. One thing I like of our Sercel equipment is the technicality of
the manuals (and in fact we was given a copy of the service manuals too)
-- furthermore, we have two copies of each, one in english and the other
in french.
> On another line, I'd question whether the average survey instrument
> facility is equipped to do EDM calibrations any better than many
> surveyors can. I certainly doubt that most facilities do much better
> than possibly testing the instrument at close ranges on a linearity > rail
> supplemented by a couple of longer measurements to verify function.
Certainly, they're not around here; I can't tell of a single
callibrated baseline in the whole region. Not only that, last week I got
me a callibration certificate for the Geodimeter 608M I'm using, an
instrument with a published DIN18723 angular error of 10cc (3.24") --
but the callibration certificate says it's actually reading horizontal
angles with a 1cc accuracy. 1cc?? it's less than a half second! How do
you suppose they can get that result (not to mention make it public)? I
don't think their collimator is even that good.
I must agree with your point here too. The question's whether you
trust more yourself or an insufficiently trained technician following
probably flawed procedures.
Regards,
Diego Berge.
Paul Koren
Gregory J. Murphy
Does the Zeiss instrument have dual axis compensators?
With respect to the DIN 18723; it is not the best specification to use
for accuracy determination. Some manufactures (Leica does) will provide
an instrument that will meet or exceed the quoted specifications. It
appears that some manufactures will quote specs for 95% (2 sigma) of the
instruments manufactured. Others it seems to be much less, sometimes I
wonder if it is closer to 38% (1 sigma) of instruments manufactured. It
is not that the instruments are junk. It just seems to take many more
observations to achieve a desired result.
cheers,
Greg.
> Kent McMillan, RPLS
> Austin TX
--
----------------------------------
Gregory J. Murphy, P.Eng.
E-Mail: gjm...@telusplanet.net
----------------------------------
Kent McMillan
>
>
> Does the Zeiss instrument have dual axis compensators?
> With respect to the DIN 18723; it is not the best specification to use
> for accuracy determination. Some manufactures (Leica does) will provide
> an instrument that will meet or exceed the quoted specifications. It
> appears that some manufactures will quote specs for 95% (2 sigma) of the
> instruments manufactured. Others it seems to be much less, sometimes I
> wonder if it is closer to 38% (1 sigma) of instruments manufactured. It
> is not that the instruments are junk. It just seems to take many more
> observations to achieve a desired result.
>
> cheers,
>
> Greg.
Greg:
No the Zeiss Elta 50 has only one compensator. One would need to
carefully level the instrument using that one compensator in order to
maximize the accuracy of horizontal angles measured with the instrument.
I have never actually seen the final version of the DIN spec for
determining the horizontal angular accuracy of geodetic instruments. The
only draft versions I've examined were based upon the analysis of
variance of rounds of directions taken to at least 5 objects from the
instrument point. I think I'd agree that for many instruments the
standard error of an angle estimated as 1.4 x s.e. direction would be
conservative, if the standard error of a direction is derived by the DIN
procedure.
I do not know what confidence level is used by Zeiss in quoting
instrument accuracy, however I'd be surprised if there is as
considerable variation in the manufactured quality of their instruments
as I'd suspect exists in some of the Pacific Rim manufacturers'
products.
David Owen
You might be pleased to find out that we have 7 service centers in the US and 2
more coming in the very near future in Texas. Please contact me and I can put
you in contact with them. They are McCully Instruments in Dallas/Ft.Worth and
Easy Drive in SanAntonio and Austin. The calibrations you wish to do can alos be
done in the field. Please contact me and I can go over this with you.
e-mail:jchwa...@zeiss.com
Sincerely,
John R. Chwalibog
Regional manager
Carl Zeiss, Inc.
Kent McMillan wrote:
David Owen
We have a number of very affordable total stations. You can purchase a
Zeiss 5" total station w/ data collection for a very excellent price. If
you would like more info please contact me at: jchwa...@zeiss.com.
Sincerely,
John R. Chwalibog
Regional Manager
Carl Zeiss, Inc.
Michael W. Gupton wrote:
> Zeiss!
> You didn't pay for it!
> I'd sure use one if our budget could afford it!
> Mike
>
Lawrence Smith
Well you certainly sparked a long line of threads with this one ! Basically
you are right in that normally we specify that the instruments fall well
within the required tolerance. Normally the housings are made to one
particular standard, and are then sorted depending on tolerance (Although
the margins are very small). The R series range has only two accuracy
specifications and so therefore many of the R50's perform way above the
required average.
If you are looking for detailed info on the instruments adjustments, most
can be found in the manual, but I can furnish you with the extra if you
like.
For reasons of the users "safety", only some adjustments like vertical
Index, horizontal collimation and compensator can be done by the user. Of
course there are many other software adjustments for trunnion axis, circle
eccentricty as well as many edm adjustments stored in the instrument. It's
easy to bugger it up if you don't fully understand what you are doing. The
R series is designed to fit a variety of different needs - from the
professional surveyor like your good self, to a construction surveyor with
basic instrument knowledge. Obviously when we design the instruments we
have to take that into condsideration.
I really hope that you don't have to send your instrument back to Jena!
Whilst I appreciate you compliments I can ensure you that we have invested
considerable monies this year in training a large number of American
dealers: most of whom I can report were highly skilled before and even
better afterwards. It's worth going to the authorised dealers because they
will have the service software. Without that you don't really stand a
chance (this is a normal practice with all instruments). There are more
checks and adjustments than you probably realise (I'm quite happy to go into
details with you if you are interested).
If you are going to the ACSM in Portland, lets have a beer together.
Best Regards
Lawrence Smith
Kent McMillan wrote in message <36DEF0...@swbell.net>...
>Gregory J. Murphy wrote:
>
Lawrence Smith
The DIN standard is used to convey the accuracy of the instrument to the
market. However, in many respects it does not give a true representation.
You will see differences in instruments with the same DIN (Albeit very
small). This will be because of the manufacturing and calibration methods
used (this can vary considerably between manufacturers).
Companies like Zeiss and Leica have a long history of fine mechanics, and
usually are slightly over-engineered - hence the fact that both are likely
to show an overperfomance.
The DIN test is not something that a manufacturer would use to calibrate the
instruments, but a conformal way to represent the accuracy.
Best Regards
Lawrence Smith
Gregory J. Murphy wrote in message <36DE1C...@telusplanet.net>...
>Hi, Kent
CHWALI
Our instruments are very affordable these days. We have routine total stations
for as little as $6500 and servo driven for 16,000. If you would like more info
about Zeiss, please contact me @ jchwa...@zeiss.com