Limitations of the measured belt： 1. Spacing: at least 20cm. 2. Width: about 1cm. 3. The thickness is not required4.like synchronous belt v-belt these can be measured, applicable to most belts HFBTE Sonic Belt Tension Tester Meter Gauge Acoustic Belt Tensionmeter For Measuring Transmission Belt Vibration Frequency With Adjustable Probe Measuring Range 10Hz-680Hz 20 Set Data Storage Product Description: It can be used to measure the vibration frequency (unit: Hertz) of the transmission belt when it is hit or moving fast. Features Adjustable probe.Can store 20 set belt parameters.Maximum frequency: 680 Hz.Automatic shutdown, etc. Measuring Principle The calculation and measurement are based on the principle of "transverse vibration of string".The tester will pick up the vibration of the belt and record it as a frequency.Enter the mass, width, and span.The relationship between frequency and tension can be calculated in the following formula：T=4xMxWxS2 xF2 x10-9 Product Parameters Measuring range:10Hz-680HzBelt free strand length:Max 9999 mmBelt width:Max 999.9 mm/RBelt mass:Max 999.9 g/mPrecision:±1HZ 100HZDigital sampling accuracy:<1%Display accuracy:土1HzOverall accuracy:<5%Operating temperature:+10° C~ +50° CTransport temperature:-5 ° C~-70° CDisplay:LCDMeasurement unit:Hz/NPower Supply:4x1.5V AAA（Betteries not included during the shipping）Housing:Plastic(ABS)Dimensions:140mmx7mm2x34mmPackage size:248mmx206mmx52mmStandard Accessories: Main UnitCarrying Case (B04)Operation Manual