Name of the standard: National Standard of Torque ZEZMS 10 kN.m
Code designation: ECM 150-11/22-68
Year of promulgation: 2022
Department: section 6252 CMI OI Kroměříž
Guarantor: Ing. Vít Petřík
Number of CMC lines provided: -
The National Standard of Torque ZEZMS 10 kN.m is a compact device with direct loading, which consists of a single system of load bodies and a moment arm of force supported by rolling bearings. The load system shall be one for both right-hand and left-hand sense of moment of force. The change of the torque sense is done by changing the installation of the arm to the right or left of the axis of rotation. The load bodies together with the torque arm realize a torque unit in the range of 0.5 kN-m to 10 kN-m. The reference device includes electrical power and control circuits for controlling the electric motor of the balancing (non-measuring) part of the load cell. The load cells are manually placed one on top of the other during calibration of the torque gauge, always in the quantity required for the measured range.
The critical parts of the reference device by which the unit of moment of force is defined are the load cells and the moment arm. The unit of moment of force is defined as the product of the force effect of the earth's gravitational field on the load bodies of a given mass and the length of the moment arm.
The National Standard of Torque ZEZMS 10 kN.m is made up of the following parts:
(a) torque standard device ZEZMS 10 kN.m (a compact single-purpose device forming a single unit), consisting of the following basic parts:
- load cell system for loading,
- a moment arm,
- the arm mounting with rolling bearings,
- the machine frame,
- the gearbox with servo drive,
- electrical switchboard,
- control panel.
b) reference torque transducer from Hottinger Baldwin Messtechnik, type TB2/10 kN-m v,
c) lifting device - column slewing crane manufacturer GANAS, type SOJ 0,125 t x 1,4 m.
Basic metrological characteristics:
The moment of force standard is intended for calibration of moment reference transducers in the range from 0,5 kN-m to 10 kN-m for loading in both right-hand and left-hand moment of force sense. The best measuring capability of the standard is with a value of Wcmc = 0,04 % of the measured force torque value. The best measurement capability of the standard is determined according to EURAMET/cg-14/v.02 as the expanded uncertainty of the calibration of the standard with an expansion factor k = 2, corresponding to a probability of coverage for a normal distribution of P = 95 %.
