Enter the Original Measurement, Total Error, and Total of All Measurements into the calculator to determine the Adjusted Measurement.

Compass Rule Adjustment Formula

The following formula is used to calculate the Compass Rule Adjustment.

Adjusted Measurement = Original Measurement + (Total Error * (Original Measurement / Total of All Measurements))Variables:

  • Adjusted Measurement is the corrected measurement after applying the Compass Rule Adjustment (units of measurement)
  • Original Measurement is the initial recorded measurement before the adjustment (units of measurement)
  • Total Error is the sum of the discrepancies in the latitudes and departures, which should ideally be zero for a closed traverse (units of measurement)
  • Total of All Measurements is the sum of all original measurements in the traverse (units of measurement)

To calculate the Compass Rule Adjustment, first determine the total error by adding up the discrepancies in the latitudes and departures. Then, divide the original measurement by the total of all measurements. Multiply this quotient by the total error and add the result to the original measurement to get the adjusted measurement. This process is repeated for each measurement in the traverse to minimize the overall error and improve the accuracy of the survey data.

What is a Compass Rule Adjustment?

A Compass Rule Adjustment is a method used in surveying to correct linear measurements for errors due to inaccuracies in the measurement process. It is based on the principle that the sum of the latitudes (north-south measurements) and departures (east-west measurements) should be equal to zero for a closed traverse (a looped path that begins and ends at the same point). If these sums are not zero, it indicates an error in the measurements, which is then distributed proportionally across all the measurements to minimize the overall error. This adjustment helps to improve the accuracy of the survey data.

How to Calculate Compass Rule Adjustment?

The following steps outline how to calculate the Compass Rule Adjustment.

  1. First, determine the Original Measurement (OM) (units of measurement).
  2. Next, determine the Total Error (TE) (units of measurement).
  3. Next, determine the Total of All Measurements (TAM) (units of measurement).
  4. Next, calculate the Adjusted Measurement (AM) using the formula: AM = OM + (TE * (OM / TAM)).
  5. Finally, calculate the Compass Rule Adjustment.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Original Measurement (OM) = 10 units

Total Error (TE) = 2 units

Total of All Measurements (TAM) = 50 units