Checkline BTM-400PLUS User Manual
Page 3
3
2.0 I
NTRODUCTION
A belt drive achieves its maximum lifetime and efficiency when:
1. It is properly configured and rated for the application.
2. The belt is tensioned to the manufacturer’s recommended tension.
3. The pulleys are perfectly aligned.
The CHECK•LINE
®
BTM-400PLUS Belt Tension Meter affords the user an easy,
reliable method for accurately measuring the tension in a belt system at standstill.
3.0 O
PERATING
P
RINCIPLE
When the Free Span* of a belt is plucked, tapped or struck, it will vibrate at a
frequency known as its “natural” frequency, the value of which depends on the
existing tension in and the total mass of the Free Belt Span, according to the
following relationship:
f = T/4dL
2
or T = 4dL
2
f
2
where:
f = Natural frequency of the Free Belt Span (Hz)
T = Tension in belt (N or lbf)
d = Belt density (kg/m or lb/ft)
L* = Length of the Free Belt Span (m or ft), which vibrates when struck.
* For definition of Free Span, refer to 4.2 and Figure 2.
The d and L parameters are fixed in the design of the belt, while the “natural”
frequency (f) varies with the applied Belt Tension (T). The BTM-400PLUS picks
up the vibration frequency of the Free Belt Span and displays it, or the corresponding
belt tension, on the instrument’s LCD display panel.
10.0 T
YPICAL
B
ELT
D
ENSITIES
10
√