Application
TTS A1571-3.0 HBM: public 7
3 Application
The transfer torque wrench is used as a transfer stan
dard for calibrating torque wrench calibrating devices.
Generally, when a torque wrench calibrating device is
used, torque is generated by exerting force on the lever
of the torque wrench to be calibrated (e.g. the triggering
torque wrench to be used in the workshop). When cali
brating the torque wrench calibrating device, on the other
hand, a transfer torque wrench (the indicating torque
wrench) is inserted into the calibrating device instead of a
torque wrench in need of calibration. The torque is gener
ated in the same way as for normal use, so that the mea
surement conditions for the calibrating device are identi
cal. This is of particular importance with respect to the
parasitic loads acting at the same time as the actual cali
bration torque, namely lateral force and bending moment.
The design of the TTS transfer torque wrench is adapted
to German Calibration Service guideline DKD‐R 3‐8 1),
which regulates the calibration of torque wrench calibrat
ing devices.
To conform to the strict requirements regarding the trace
ability of a transfer standard, a transfer torque wrench
must be calibrated in an accredited calibration laboratory
(in Germany, this is a DKD laboratory). The DKD calibra
tion certificate in accordance with guideline DKD‐R 3‐7 2)
has to be ordered separately.
1) Guideline DKD‐R 3‐8 “Statische Kalibrierung von Kalibriereinrichtungen für Drehmoment
schraubwerkzeuge" (Static calibration of calibrating devices for torque tightening tools), pub
lished by the German Calibration Service.
2) Guideline DKD‐R 3‐7 “Statische Kalibrierung von anzeigenden Drehmomentschlüsseln“ (Static
calibration of indicating torque wrenches), published by the German Calibration Service.
