Load Application; Mounting With Knuckle Eyes - HBM RSCC Notice De Montage

RSCC

5.2 Load application

The RSCC type series load cells can measure axial loads in the tensile
direction. Load is applied via two tapped holes. The loads must act as
precisely as possible in the load direction of the load cell. Torsional and
bending moments cause measurement errors and can permanently damage
the load cell. Interference effects must be absorbed by suitable construction
elements, whereby these elements must not absorb any loads in the load
direction of the load cell. HBM recommends the use of knuckle eyes for
connection without side force or moments. They are suitable for use with
quasi‐static loading (load cycles v10 Hz).

5.3 Mounting with knuckle eyes

Knuckle eyes prevent the application of torsional moments on the transducer
and also, when 2 knuckle eyes are used, bending moments, together with
lateral and oblique loadings.
Mount the knuckle eyes applying pre‐stressing to the transducer
(recommended mounting variant):
1. Unscrew the locknut up to the eye
2. Screw the knuckle eye into the transducer (note permissible thread reach)
3. Unscrew the knuckle eye 1 to 2 threads, and align it
4. Load the knuckle eye at 110% of the operating load in the tensile direction
5. Hand‐tighten locknut
6. Relieve the load
Alternatively, you can also mount the knuckle eyes by tightening the locknut of
the knuckle eye with a defined torque:
1. Unscrew the locknut up to the eye
2. Screw the knuckle eye into the transducer (note permissible thread reach)
3. Align the knuckle eye
4. Tighten the locknut with the torque given below
Maximum
capacity (kg)
50 to 100
200 to 1000
2000 to 5000
A3018-3.2 en/de/fr
Load cell thread
M8
M12
M24x2
Tightening torque (NVm)
15
50
200
11
HBM