Hi guys

Can anyone help me with this attached pic 

A formula for it or any information would be appreciated

Kind Regards


This Content Originally Published by a land surveyor to Land Surveyors United Network

Views: 579

See Your Saved Posts Timeline

☇ Reply to this

Replies to This Discussion

I amnot 100% sure of the abbreviation LNSF or INSF. The lower case is ambiguous to my eye. 

When I look at the form in total, I am leaning toward a meaning of Linear Scale Facor as a percentage of length and as a resulting distance calclated from it.

Again, interpreting this form, I believe the scale factor is a characteristic of the projection and your location within it.


In sf would be instrument scale factor. This would probably come from the manufacturer of the instrument used (?).
I don't know if this will help or not but I believe that the abbreviation Delta INSF means change in scale factor. I'm not sure why one of the units would be in parts per million and the other would be in meters. In algebraic expressions, the Delta symbol almost always indicates change or difference.

I assume the previous replies are correct. Using an electronic total station - one may be invited to enter temperature, barometric pressure and relative humidity. When that is entered the display shows a scale factor for the EDM.

I believe the form is laid out in such a way that one figures the scale factor as a percentage. Then the user multiplies the raw length by the scale factor to determine the linear quantity result of applying the SF. The linear quantity is added to (or subtracted from) the raw quantity to determine the final, useful quantity.


Computed distance/measured distance



Where Thousands of Professional Land Surveyors, Students of Surveying and Educators are United through Collaborative Knowledge and Purpose.

Land Surveyors Forum

modern method of stereo model

Started by shree ram bhandari in Surveying Documents 6 hours ago. 0 Replies

Survey Abstract Coordinates

Started by John J Rodriquez in Surveying Best Practices. Last reply by Donald E Robinson, PLS, CFS 19 hours ago. 16 Replies

Control surveying problem

Started by shree ram bhandari in Land Surveying Jobs. Last reply by Billy Brooks on Saturday. 11 Replies

Magnetic North Update

Started by Billy Brooks in Surveying Best Practices. Last reply by Billy Brooks Feb 6. 2 Replies


Started by Lalith Senanayake in Surveying Related Links. Last reply by shree ram bhandari Feb 12. 4 Replies

Job Quotation

Started by Nitesh Shrestha in Land Surveying Jobs. Last reply by Nitesh Shrestha Jan 21. 3 Replies

Survey under tree canopy

Started by Massimo in Surveying Best Practices. Last reply by Maurice Heter on Saturday. 7 Replies

Mean Sea Level (MSL)

Started by Chuck Turlington in Geospatial Industry Types. Last reply by Kim Noblitt Jan 17. 6 Replies

Surface pro

Started by Malik in Surveying Field Tips and Tricks. Last reply by Kevin D. Allen Jan 7. 5 Replies


Started by Mthulisi Mloyi in Professional Advice for New Surveyors. Last reply by ⚡Survenator⌁ Jan 4. 2 Replies

Tools,Apps and Quick Guides


Help With Survey Equipment

Social Support For Equipment

Surveying Video Categories

Surveying Photo Categories

United States Hub Forums

International Surveyor Hub Forums

Resources for Company Owners

Land Surveyor Social Media

Surveyor Resources Collections

Getting Started & Newsletter

Featured Land Surveyor Hubs

Surveyor Birthdays

© 2019   © Created by Land Surveyors United   Powered by

Badges  |  Contact LSU  |  Privacy Policy  |  Terms of Service

Site Explorer