burster Italia s.r.l. ·
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· Sede legale ed operativa ·
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· Via Cesare Battisti, 16/18 · 24035 Curno (BG) · Tel. +39 035 618120 · Fax +39 035 618250
e-mail: [email protected] · http://www.burster.it
C.F. e P.IVA 11048400151 · Capitale sociale Euro 49.920,00 ···· R.E.A. di Bergamo 276749
Apparecchi di misura di precisione. Sensori e Sistemi
per grandezze elettriche, termiche e meccaniche
6
Measuring
6.1
Engaging
The warming-up period of the torque sensor is approx. 5 min. Afterwards the measurement can be started.
The warming-up period of the torque sensor is approx. 5 min.
6.2
Direction of Torque
Torque means clockwise or clockwise torque if the torque acts clockwise when facing the shaft end. In this case a positive
electrical signal is obtained at the output.
Torque sensors by burster can measure both, clockwise and counter-clockwise direction.
6.3
Static / Quasi-Static Torques
Static and/or quasi-static torque is a slowly changing torque.
The calibration of the sensors occurs statically on a calibration device.
The applied torque may accept any value up to the nominal torque.
6.4
Dynamic Torques
6.4.1 General
The static calibration procedure of torque sensors is also valid for dynamic applications.
Note: The frequency of torques must be smaller than the natural frequency of the mechanical measurement setup.
The band width of alternating torque must be limited to 70 % of the nominal torque.
6.4.2 Natural Resonances
Estimate of the mechanical natural frequencies:
+
⋅
⋅
⋅
=
2
1
0
1
1
2
1
J
J
c
f
π
f
0
J
1
, J
2
c
= Natural Frequency in Hz
= Moment of Inertia in kg*m²
= Torsional Rigidity in Nm/rad
Further methods for the calculation of natural resonances are corresponding purchasable programs or books (e.g. Holzer-
Procedure, Dubbel, Taschenbuch für den Maschinenbau, Springer Verlag)
An operation of the device in natural resonance can lead to permanent damages.
6.5
Speed Limits
The maximum speed indicated in the data sheet may not be exceeded in any operating state..
6.6
Disturbance Variables
By disturbances, measured value falsifications can occur by
•
Vibrations,
•
Temperature gradients,
•
Temperature changes,
•
Arising disturbance variables during operation, e.g. imbalance,
•
Electrical disturbances,
•
Magnetic disturbances,
•
EMC (electromagnetic disturbances),
Therefore avoid these disturbance variables by decoupling of vibrations, covers, etc.
c
J
1
J
2
