Leica DISTO Self Calibration Instructions
Self Calibration Done Easy
Quality relevant test equipment
Within the framework of monitoring the accuracy of distance/angle measurements, the quality relevant test equipment must be monitored, maintained and calibrated in regular intervals. These calibrations must be retraceable to national standards and performed with the appropriate equipment. Every manufacturer determines which tests are relevant to the quality of its products. The tests should be appropriate for the relevant process and serve to maintain high and stable product quality.
Calibrate it yourself
The monitoring of Leica DISTO distance meters by ISO 900... : certified users.
You can perform the ISO 900... standard of requirements for monitoring distance measurements with the Leica DISTO™ on your own. Select a permanently constant and easy to access baseline of known length, from approx. 1 to 10m (e.g. a window frame or the width of a room) and take at least 10 measurements (we recommend 20 measurements). The length the baseline must be determined with measuring equipment, e.g. a class II or I steel measuring tape approved by your national bureau of standards (Traceability to national standards. The class II or I Roman stamp is sufficient)
Calculation of accuracy:
Determine the average of the measured values and calculate from it the systematic deviation from the actual distance of the baseline. Then calculate the standard deviation according to the following formula:
The typical accuracy of the meter is calculated by adding the systematic deviation to 2x the standard deviation. Calculation aid for Excel - please check the downloadable file (Calibration_aid.xls)
Approximation of accuracy:
For an approximation of calculated accuracy, just average the deviations of the measurements to the actual distance. This value must be within the specified typical accuracy of the meter. Record the value and set the time for the next series of measurements. Repeat these check measurements regularly, especially before and after important measuring tasks. Mark the Leica DISTO with an ”inspected” sticker and record the entire monitoring process. Please check the technical data and the specifications to the measuring accuracy in the User Manual.
You can perform the ISO 900... standard requirements for monitoring angular measurements with the Leica DISTO on your own.
To check the accuracy of the slope sensor in the 0° range, place the meter on a long spirit level (>1m), approved by your national bureau of standards (Traceability to the national standards). You can now determine the deviation of the Leica DISTO in regards to the laser beam or to the casing.
Calculation of accuracy for the slope sensor in regards to the laser beam:
Align the spirit level, which serves as a base for the Leica DISTO to the horizon as precisely as possible and project the height of the top surface of the spirit level with a second spirit level or leveling device to a vertical surface (e.g. a wall) from a distance of approx. 3-10m. Now take the height of the laser beam aperture above the casing of the Leica DISTO (16mm) into account and make the corresponding mark on the wall. Set the Leica DISTO on the spirit level and switch the meter to Pointing Mode. Underlay one end of the Leica DISTO until the center of the laser dot hits the mark on the wall. Take at least 10 angle measurements (we recommend 20 measurements).
Determine the average of the measured values and calculate from it the systematic deviation to the 0° angle. Then calculate the standard deviation according to the following formula:
The typical accuracy of the meter in regards to the laser beam is calculated from the systematic deviation plus 2x the standard deviation.
Approximation of accuracy:
As an approximation of calculated accuracy, just average the measured values. This value must be within the specified typical accuracy of the meter.
Calculation of accuracy of the slope sensor in regards to the casing:
Align the spirit level, which serves as the base for the Leica DISTO as horizontal as possible. Take at least 10 angle measurements (we recommend 20 measurements). To calculate the measurement deviation in regards to the casing, process analog to the calculation of the accuracy of the slope sensor in regards to the laser beam. Record the value and set the time for the next series of measurements. Repeat measurements regularly, especially before and after important measuring tasks. Mark the Leica DISTO with an “inspected” sticker and record the entire monitoring process.
Please check the technical data and the specifications of the measuring accuracy in the User Manual.
Should you want to check a random angle in regards to the casing, we recommend you use a so-called sine bar and spirit level that is as long as possible (>1m) as base. Both should be approved by your national bureau of standards (Traceability to the national standards). Align the spirit level as precisely as possible to the horizontal. With the sine bar, any known angle can be precisely set. Set the meter on the sine bar and take at least 10 measurements of the same angle (we recommend 20 measurements).
To determine or evaluate the measured results, precede analog to the description of the distance measurements; by referencing the average value to the design value of the angle (predetermined with the sine bar).
Calibration by Leica (available for Leica DISTO A8, D5 and D8)
Leica Geosystems offers a calibration service for the Leica DISTO A8 and D5 (not available for other Leica DISTO distance meters).We recommend, making use of this service once a year. Your distance meter will be returned to you with a renewal of the Producer Inspection Certificate M in accordance with DIN 55350-18-4.2.2 The measured values and deviations in the renewed certificate may differ from the original certificate, because the meters are readjusted at Leica Geosystems and the measurement parameters may have been reset.
To make use of the Leica Geosystems calibration service, please send your Leica DISTO (A8 or D5 or D8) to the following address:
Leica Geosystems AG
MTD Calibration Service
Heinrich Wild Strasse
For further information, please visit firstname.lastname@example.org
The fee for the Leica calibration service is 150. - EURO worldwide (incl. return shipment). Payment is due 30 days after the invoice date without discount. The calibration may take 2 to 3 weeks depending on the required work and the shipping time involved.
Calibration by independent institutions
Just about in every country there are independent institutions that offer calibration services for distance meters. They however, cannot adjust and change the measurements parameters.