Hapeman Calibration
As a test engineer for more than 25 years I have seen a number of changes and advances in the test and measurement business. When I started in the 1980’s only the military and major corporations could afford to think about automated testing. The cost, complexity and tools available made it difficult and time consuming to develop an automated test system. The first system that I worked on in the late 1980’s cost 100’s of thousands of dollars and took over 3 years to develop.
As time went on computers, test equipment and communication standards helped lower the cost and time required to develop new automated test equipment. Calibration of this equipment used a combination of manual standards and computer calibration constants that were allocated in each system with a unique design as the programmer saw fit to use. Calibration was always the last thing considered and each system required knowledge of the programs running in the system to change.
Another big problem with test system calibration was trying to determine and measure system capability and how well the measurement agreed with national standards. In 2006 ISO developed the 17025 standard that provided a basis for providing end to end traceability of the measurement. This system of accreditation allowed documentation of the chain of comparisons and using this data, a statistical method (ILAC) was standardized to estimate how closely the instrument that is being calibration should agree to national standards. With the proper calibration, NIST standard traceability could be documented, and test system measurement capability could be determined. Results from different labs making the same measurement can compare results and take into account the quality of the calibrations and traceability. The ISO 17025 standard also created a standard outline of the calibration organizations quality system and competency.
When Hapeman started designing and building test systems we contracted calibration companies for calibration. Since there were not many companies providing ISO standard calibrations. the quality of a calibration provided could not be readily determined. Comparisons between labs and test stands were not ever in agreement and it always came down a opinion if they were “close enough”. Hapeman also had problems where the “standard” calibration that was done was not done in the range that the instrument was used. We had a major instrument manufacturer that calibrated only full range on each input but was far off when checked at measurement levels that the customer was using. Problems with calibration were the main cause of customer complaints.
To address this problem and to improve the performance of our test system Hapeman began investing in calibration standards several years ago. We began checking calibration on our new systems and on our existing systems. We pursued getting calibration accreditation so that confidence in our calibrations and procedures conform to standards. Calibration has helped us to provide a basis for comparing the equipment and instruments that we use and allow us to provide test system capability estimates that our customers have confidence in.
Our future goal in calibration is to expand the scope of our accreditation with new standards. We also are improving our DAQ software to provide calibration control and tracking so that each test performed on one our test stands will provide accurate data and reports on the status of calibration as part of the test report done for each test. This calibration report will include an estimate of the uncertainty of the measurements and allow the easy preparation of lab reports WITH DATA THAT CAN BE TRACED.
Hapeman is excited about what this capability will do for our competitive position and the effect it is bound to have with the satisfaction of our customers.
