3
4
Fig.1 OsciIlation attenuation of timing belt
150
100
50
0
50
100
150
２
Timing beit：
３GT tooth shape × 3mm wide
（V）
０
-２
TIME A
LIN
８０mS
２. Brief summary, caution & check points for failure
３. Measurement principle of U-550
The sonic belt tension meter (U-550) is
the handy equipment which enables to
measure the tension accurately by
analyzing sonic wave without touching.
A sensor catches the produced
eruption of sound wave by pick the belt
span. After that, the high processing
computer analyzes it and shows the result
on the screen digitally.
When we make a belt between pulleys
vibrate by giving impact, it starts to
oscillate irregularly as seen in Fig.1, but
gradually it oscillates an inherent regular
moves.
The U-550 tension meter was created to
address this phenomenon. In the past,
there was no easily implemented device
which could catch these small waves.
We succeeded in catching the period of
wave pattern relatively easily by
developing a data handling method to
capture the vibration frequency that made
full use of microcomputer.
As for the system, sensor detects the
vibration waveform, microcomputer
calculates the character vibration number
by processing the data.
To calculate the belt tension, we use the
transverse vibration of the thread for
setting at a tension as right side.
Here, the belt and the wire have a rigidity,
which is different from the string, therefore
U-550 measurement displayed is
somewhat higher than the actual tension
under the affected condition.
Therefore, it is possible to obtain
correction factor by strict calibration test
and incorporate it to the data input,
thereby it can display more accurate
tension.
An example of calibration result of U-550
measurement and actual tension is shown
below:
Calculation To＝４×M×W×S
２
×f
２
×１０
-９
To： Tension
M： Unit mass
W： Belt width or number of ribs（wires）
S ： Measured span length
f
： Horizontal characteristic frequency
（N）
（g/mm width × m length）
（mm/R）
（mm）
（Hz）
■ Brief summary
■ Check points for the immeasurable state
［Failed to measure or the results were fluctuated significantly.］
ITEM
＊Please inquire to us or the dealer where you purchased if the U-550 does not work after checking
the points above.
PRESUMED
PRESUMED CAUSE
CONFIRMATION PONT
"Error" shows up or
the measure mode
can not be engaged
or the red light on.
The unevenness of
the output level is
large.
● Nothing shows
up or only
measuring
processing sign
shows up from
the third time of
measurin
（Frequency
mode）
● The measured
value changes
every time greatly
● The sensor
responds to the
background noise
keenly
● "0" is entered to the unit mass,
width & span
● Input the wrong frequency range
● Measured frequency exceeds
5000Hz or below 10Hz
● Battery drain
● The sensor attaches to a belt for
a moment
● Automatic gain adjustment is not
enough
● Check the entered data（Input
the correct number）
● The frequency displays, but the
tension does not measure
● Change the measurement
frequency range
（LOW（V） ⇔ STANDARD ⇔HIGH）
● Check whether the measurement
frequency exceeds 5000Hz or
not
● Battery drain
● Measure again keeping enough
distance so that the sensor does
not attach to a belt
● Turn off a power once at the
measurement place, then turn it
on
（Turn on a power with
connected the sensor, then push
"MEASURE" button after one
second
Therefore, it is required to input the length of
span to be measured and the mass of beIt
（unit mass x width） by use of numeric key.
3GTbalt
Actual tension（N）
U-550 measured value（N）
：Span length 86mm
：Span length 154mm
：Span length 365mm
：Span length 365mm
［9 mm wide］
Standard instalation
tension of belt
9 mm wide
Standard instalation
tension of belt
6 mm wide
［6 mm wide］
Fig.2 U-550 relation between measured
value and actual tension
0
100
200
300
400
500
600
100
200
300
400
500
600
Actual tension（N）
U-550 measured value（N）
Typical terision when
sfrbtching again
Typical
lnstallation
tension
V-ribbed belt
：Span length 102mm
：Span length 201mm
：Span length 400mm
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2020/12/08 16:18
