User's Guide

This document is subject to change without prior notification.
Binsfeld Engineering Inc. | 231-334-4383 www.binsfeld.com 869610-9_A2 Pg. 38
Torque on Round Shafts
Step 1: Calculate Full Scale Torque, T
FS
(ft-lb)
The Full Scale Torque corresponds to a system output of 10 V. For a
solid steel shaft, use the calculator on our website at www.binsfeld.com
or use the simplified equation below:
For all other shafts use the more general equation:
For metric applications with D
o
and D
i
in millimeters and T
FS
in N-m, the
general equation is:
Where E= 206.8 x 10
3
N/mm
2
Legend of Terms
D
i
Shaft Inner Diameter (in) (zero for solid shafts)
D
o
Shaft Outer Diameter (in)
E
Modulus of Elasticity (30 x 10
6
PSI steel)
GF
Gage Factor (specified on strain gage package)
G
XMT
Telemetry Transmitter Gain (user configurable, typical
is 4000 for ±500 microstrain range)
N
Number of Active Gages (4 for torque)
T
FS
Full Scale Torque (ft-lb)
(V
FS
)()(E)(4)(D
o
4
-D
i
4
)
───────────────────────── = T
FS
(ft-lb)
(TX
const
)(GF)(N)(16)(1+)(G
XMT
)(D
o
)(12)
(1510.38 x 10
3
ft-lb/in
3
)(D
o
3
)
───────────────── = T
FS
(ft-lb)
(GF) (G
XMT
)
(V
FS
)()(E)(4)(D
o
4
-D
i
4
)
───────────────────────── = T
FS
(N-m)
(TX
const
)(GF)(N)(16000)(1+)(G
XMT
)(D
o
)