Background Noise; Sonic Tension Meter Operating Theory - Gates 550C Manuel D'utilisation

550C
GATES SONIC TENSION METER MANUAL
(900-5000 Hz) will be displayed. Choose a range
with the "UP" or "DOWN" button, and determine
with "MEASURE".
Note:
The letter in the upper left hand corner of the OLED
display indicates the frequency range setting pointer
(5) on page 4: H - High, S - Standard, L- Low.

BACKGROUND NOISE

The microphone gain level is set automatically when
the unit is turned on, based upon environmental
background noise.
Note:
If maximum microphone sensitivity is desired, turn
the meter on without the microphone attached and
wait for the meter to power up. Then connect the
microphone so tension measurements can be taken.
BATTERY GAUGE
A battery graphic is located in the upper-right hand
corner of the OLED screen. This gauge provides an
estimate of the remaining battery power.
A dark filled graphic indicates a full charge. When
the battery level becomes critically low, the meter
indicator as well as a "Low Batt" message both blink.
4. SONIC TENSION METER
OPERATING THEORY
When an impulse is applied to a belt span, it first
oscillates in all modes of vibration, but the higher
frequency modes decay faster than the fundamental
mode. This leaves a continuous sinusoidal wave
that is related to a specific belt tension. See the
following diagram:
6
2
3MGT - PowerGrip
0
-2
0
Time (millisecond)
Oscillation damping in a synchronous belt
Using a microcomputer, a data processing method
to capture a belt's natural oscillation frequency
was developed. Using this method, the wave form
frequency can be determined easily.
The new system uses special sensors to detect belt
oscillation wave forms. Data from these sensors
is sent to the microcomputer inside the Sonic
tension meter for processing and conversion into
the natural frequency. To calculate belt tension, the
Sonic tension meter system uses the "transverse
vibration of strings theory". To operate the meter, the
unit weight, span length and width of the belt must
be entered.
Formula: T = 4 x S x M x W x f
2
Where:
T = belt span tension (Newton)
S = length of the span to be measured (mm)
M = belt unit weight (g/m/mm)
W = belt width (mm) or number of belt strands
f = natural frequency of the belt (Hz)
Unlike a string, belts have cross-sectional rigidity.
Therefore, tension values measured by the meter
may be higher than the actual belt tension,
depending on the operating conditions under which
the effects of rigidity arise. When the actual belt
tension must be more precisely measured, a simple
calibration test may be necessary. This calibration
procedure is discussed in the section on "Meter
recalibration for non-standard belts".
GT3 9
™
mm width belt
80
x 10
2 -9
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