Tension Electronics PFEA113, User Manual
Section A.2.1 Coordinate System
3BSE029382R0101 Rev C A-3
A.2.1 Coordinate System
A coordinate system is defined for the load cell. This is used in force calculations to derive force 
components in the load cell principal directions.
Where direction designations R, V and A are recognized as suffixes for force components, F, 
this represents the force component in the respective direction. The suffix R may be omitted, 
when measuring direction is implied by the context.
Figure A-1. Coordinate System Defining Directions used in Force Calculations
T = Web tension.
Tare = Force of tare (weight of roll and bearing arrangement 
mounted on the load cells)
F
R
 = Measured force (force component of the web tension 
in the measuring direction of the load cell).
F
RT
 = Applied force component of tare in the measuring 
direction of the load cell.
F
Rtot
 = Total applied force in the measuring direction of the 
load cell.
Wrap Gain = The ratio between web tension, T, and 
measured force, F
R
.
Table A-1. Definitions
T
T
F
R 
F
R 
= T
Wrap angle
= = 1.00
Wrap gain = 
Wrap gain 
Wrap gain = 1.00
T
F
R
T
T
Example:
R
V
V
R
A
A
R = Measuring direction
V = Transverse direction
A = Axial direction
V
R
R
V
A
A