Just a sticker? The value behind certifying your measurement instruments

Proving that your total station or MultiStation is within specification is crucial to assure the services that you provide deliver the right standards and accuracy. In this Q&A Wolfgang Hardegen, Manager of the Leica Geosystems Accredited Calibration Laboratories, based in Heerbrugg, Switzerland talks about the highly accurate calibration services for total stations and MultiStations offered by Leica Geosystems.

Wolfgang, what makes Leica Geosystems’ calibration service facilities special?

Leica Geosystems is the only surveying instrument manufacturer in the world running accredited calibration laboratories for distances and angles in-house, which issues calibration certificates in accordance with ISO/IEC 17025 granted by the Swiss Accreditation Service (SAS).

Since 1997 we run Accredited Calibration Laboratories that offer a variety of calibration certificates here in Heerbrugg, Switzerland. Calibration certificates by accredited laboratories ensure the accuracy of the surveying equipment. Having such highly accurate in-house laboratories gives Leica Geosystems a big advantage – during development and manufacturing we have at any time the possibility to perform tests in our laboratories.

Why is calibration of a total station or MultiStation so important?

From time to time, it is necessary to send an instrument to service for calibration. Calibration makes sure that the instrument meets the manufacturers specifications and customer’s requirements regarding measurement accuracies.

Leica Geosystems offers 4 levels of calibration, Gold, Silver, Bronze and Blue, which confirm the measurement quality of new or used surveying equipment.

For more information about calibration certificates read the white paper or visit the Leica Geosystems calibration certificates page.

Leica Geosystems is offering a wide range of calibration certificates. What is special about the Calibration Certificates Gold?

Our Certificate Gold is a special calibration certificate which may only be issued by an Accredited Calibration Laboratory. Such a high-level calibration is perfect for total stations and MultiStations which are used by ISO 9001 certified companies and for major projects and tenders with public interest (e.g. public health, public safety or selected legal procedures).

Calibration certificates issued by Accredited Calibration Laboratories are internationally acknowledged according to the ILAC MRA (Mutual Recognition Agreement). The test results are directly traceable to national standards and they include measurement uncertainties with detailed measurement reports.

How is accreditation organised internationally?

Within a global approach in cooperation with the World Trade Organisation (WTO), certificates are internationally recognised in over 100 countries. The WTO has established the International Laboratory Accreditation Cooperation (ILAC), who manages international arrangements. The regional arrangements in Europe are managed by the European Cooperation for Accreditation (EA), one of worldwide five regional co-operation bodies that work in harmony with ILAC. National accreditation bodies like the Swiss Accreditation Service (SAS) are members of these international organisations and are responsible for the accreditation of laboratories.

To find official information about the Leica Geosystems Accredited Laboratories, please visit the Swiss Accreditation Service (SAS) website and select SCS 0079. The document lists the test capabilities with the specific measurement accuracies and uncertainties the Leica Geosystems Accredited Laboratories have.

What are the efforts to run accredited laboratories for the calibration of total stations?

Leica Geosystems' basis to gain the status of an accredited laboratory is the quality management system in accordance with ISO 9001. Additional to the technical infrastructure and highly trained and qualified staff, every single calibration process which we use in the laboratories must be checked, verified and accepted in detail by external experts from the national accreditation body (SAS).

Yearly audits by the SAS in accordance to ISO/IEC 17025 make sure that the laboratories keep the highest possible standards during the operation. Every five years the accreditation must be renewed by the Swiss Accreditation Service (SAS) through an extensive audit.

How many accredited calibration laboratories does Leica Geosystems have and what purpose does each laboratory have?

We run four calibration laboratories and a test laboratory.

1. Calibration Laboratory for Angles

Calibration of angles is a very difficult and elaborate task. Worldwide there are only a few institutions who can offer a similar high accuracy.

Since we could not find an institution offering the measurement quality we would have expected, we decided, about 20 years ago, to develop the first theodolite testing machine (TPM) on our own. This complex machine automatically checks the horizontal circle and zenith angles. With a measurement uncertainty of 0.09” (Hz und V), this testing machine is highly accurate.

2. Baseline Open-Air Laboratory

Situated open-air on the bank of the Rhine river, the baseline open-air laboratory is not a typical laboratory. It consists of 7 pillars with a straight line of sight with no obstructions up to three kilometres. This allows us to check the standard deviation of distance measurements over long lengths of 500 m, 1,000 m, 2,000 m, or 3,000 m. During this exercise, we accurately determine atmospheric parameters, such as temperature, pressure, and humidity, crucial to achieve the highest accuracy.

3. Calibration Laboratory for Distance

In the Calibration Laboratory for Distance we determine absolute distance deviations and deviations from linearity over distances of 60 m and 120 m. The results from the tested total stations are compared with the results of a highly accurate interferometer.

4. Calibration Laboratory for Frequency

In simple words, in this laboratory we check the accuracy of the scale of electronic distance meters (EDM) by comparing the output frequency with a reference frequency. This is done in a climate chamber that is set to several temperatures between - 20° C and + 50° C.

5. Test Laboratory for Laser Classification

In this laboratory, we measure the output power of lasers to classify the laser.

In conclusion, customers sending their instruments to the Leica Geosystems Accredited Calibration Laboratories can be sure that all steps will be correctly executed and their equipment is in the best hands.

Wolfgang, thank you for sharing your insights with us.
The pleasure is mine.

Wolfgang Hardegen
Manager Accredited Laboratories
Leica Geosystems AG, Heerbugg, Switzerland