Process reliability in the screwdriving technology
With a calibration from DEPRAG you can always be sure that your measurement equipment provides reliable measurement results – competent and with the requisite traceability to national norms. DEPRAG has an accredited calibration laboratory where various calibration methods can be employed to calibrate with traceability and the lowest measurement uncertainty, covering torques of between 0.01 Nm and 500 Nm.
How long is the calibration valid?
In principle a calibration is only valid at the time it is conducted. It is normally the responsibility of the user to decide on the length of calibration intervals. The application, i.e. the conditions of the workplace, method of usage of the measurement tool, frequency of use and safety concerns for the workpieces to be assembled are all considerations when determining calibration intervals.
If a measurement tool is used in a running assembly process, it makes more sense to have shorter calibration intervals than if a measurement tool is only used infrequently in a laboratory setting.
Verification cycles could then perhaps take place every 3 months or 3 years.
We recommend recalibrating our measurement system at least once a year.
Calibration of DEPRAG torque transducers
In the accredited calibration laboratory DAkkS and factory calibrations of torque measurement transducers are carried out in conformity with validated procedures. The documentation of results is presented in a calibration certificate containing all measurement values and the corresponding measurement uncertainties. Depending on the application and desired measurement uncertainty, the number of calibration procedures conducted can be increased or decreased to differentiate between direction of load, number of installation points, as well as attained measurement uncertainties. Measurement transducers based on strain gauge and piezo technology can also be calibrated. Calibrations can be conducted either in conformity with DIN 51309 or VDI/VDE 2646 (calibration procedures). The calibration is usually spread over 8 torque steps in a span of 10%-100% of the measurement range.
Calibration equipment is available for the torque range 0.01 Nm – 500 Nm.
All measurement transducers from DEPRAG are calibrated in the standard measurement range on delivery (see product catalogue D3020E). Specialized calibrations for atypical measurement ranges are available on request.
Calibration service for torque transducers from other manufacturers
All calibration procedures mentioned are also available for the calibration of torque measurement transducers from other manufacturers. To verify the suitability and determine a suitable procedure, we require information relating to the technical implementation of the transducer, the application conditions and required measurement uncertainty.
We will be pleased to answer any questions you have regarding the calibration of torque transducers from other manufacturers.
To analyse the capability of a measurement system consisting of torque transducer and measurement electronic, we conduct measurement system analyses in conformity with procedure 1 in our DAkkS accredited calibration laboratory (DIN EN ISO/IEC 17025). The result confirms the suitability of a measurement system for a specific application by determining the capability values.
The measurement system analysis is conducted using the specified test torque.
In essence all components of the measurement chain are calibrated separately. Measurement devices for the piezo transducer are subjected to a comparison measurement and realigned if required using a charge calibration device and measurement devices for the strain gauge transducer with a strain gauge calibrator. The standards used for DAkkS and factory calibrations follow national norms and therefore fulfil the highest quality requirements. The measurement transducers are calibrated and documented in our own calibration laboratory in conformity with standardised calibration procedures.
Factory calibration of measurement devices / measurement electronics
The measurement devices or measurement electronics are function tested. At the same time, the calibration value is determined for the measurement cell. The results are documented in a protocol, the manufacturer’s verification certificate. Calibration activities are based on currently valid norms, in particular DIN EN ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories).