Prism constant for Nikon mini-prism in corner
Prism constant for Nikon mini-prism in corner
I'm new here, and a retired avionics / radar engineer with an interest in surveying archaeological sites such as stone circles in Wales.
In the past I've used a Wild T2 theodolite with a Disto Basic mounted above and parallel to its telescope, and measuring angles and ranges to a custom designed detail target. This although slow and non-automated has worked well with good accuracy. (3mm or better)
I've now bought a Nikon mini-prism kit as in the link, and am totally baffled with the concept of prism constant with this particular device. The prism constant is 0 according to the Nikon information, so does this mean that the Total Station measures correctly to the mechanical axis of the prism holder? If so, I don't understand the purpose of the accessory holder designed to support the prism in a corner of a building. The corner holder accessory is designed to allow the rear apex of the prism to get into the corner, and it does get in to within 2mm. BUT, this is some 15mm away from the plane of the prism which aligns with its other mounting device.
I've downloaded the manual for a Nikon Total Station. but whilst comprehensive, it's silent on the above point.
(I fully appreciate that I can't use a prism with my Disto Basic.)
Whilst I'm asking about this, is a '0' prism constant the same for different makes of Total Station?
Many thanks - from England.
In the past I've used a Wild T2 theodolite with a Disto Basic mounted above and parallel to its telescope, and measuring angles and ranges to a custom designed detail target. This although slow and non-automated has worked well with good accuracy. (3mm or better)
I've now bought a Nikon mini-prism kit as in the link, and am totally baffled with the concept of prism constant with this particular device. The prism constant is 0 according to the Nikon information, so does this mean that the Total Station measures correctly to the mechanical axis of the prism holder? If so, I don't understand the purpose of the accessory holder designed to support the prism in a corner of a building. The corner holder accessory is designed to allow the rear apex of the prism to get into the corner, and it does get in to within 2mm. BUT, this is some 15mm away from the plane of the prism which aligns with its other mounting device.
I've downloaded the manual for a Nikon Total Station. but whilst comprehensive, it's silent on the above point.
(I fully appreciate that I can't use a prism with my Disto Basic.)
Whilst I'm asking about this, is a '0' prism constant the same for different makes of Total Station?
Many thanks - from England.
I seem to remember that Leica 0mm offset settings in the software actually have a (-34mm offset) physically. I would think that if you used a Leica mini prism with a zero offset setting, and then used a larger Leica prism with the same setting, you SHOULD be okay. I second what Dave said.
Prism compatibility for total stations
Prism compatibility for total stations
![Mini Mini](/uploads/1/2/5/2/125207595/248552986.jpg)
I recently acquired an older total station (Wild Heerbrugg / Leica TC 1000) that I would like to use to do some occasional topo surveying and construction staking.
I don't have a prism or prism pole. So my question is, are only certain models/kinds of prisms compatible with my instrument in order to get an accurate distance measurement? Will using the wrong prism give me incorrect distance readings? Does my instrument need to be calibrated to the specific prism manufacturer/model somehow? Or will any decent prism make/model be accurate?
(No manual with the instrument, so if anyone knows of a good source of old equipment manuals that would also be helpful. I found this site: www.surveyors.de - which has the manual in Spanish as a free pdf download but not in English.
Thanks!
I don't have a prism or prism pole. So my question is, are only certain models/kinds of prisms compatible with my instrument in order to get an accurate distance measurement? Will using the wrong prism give me incorrect distance readings? Does my instrument need to be calibrated to the specific prism manufacturer/model somehow? Or will any decent prism make/model be accurate?
(No manual with the instrument, so if anyone knows of a good source of old equipment manuals that would also be helpful. I found this site: www.surveyors.de - which has the manual in Spanish as a free pdf download but not in English.
Thanks!