Overview: This instrument can be used to measure the vibration frequency  (unit: Hertz) of the transmission belt when it is hit or moving fast.The  tester uses a microphone mounted at the end of the measuring probe  for measurement.After measuring in Hertz, the tester can use this  data to calculate the belt tension in newtons. NOTE: The operation of the is reliant on the correct belt  informationbeing inputted.Please ensure the correct belt  manufacturers' data is used Features: *Adjustable probe. * Can store 20 set belt parameters. * Maximum frequency: 680 Hz. * Automatic shutdown, etc. 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 in the following formula.frequency The relationship between and tension can be calculated in the following formula& 65306; T=4xMxWxS2 xF2 x10-9 Specifications:       Measuring range    10Hz-680Hz        Belt free strand length    Max 9999 mm        Belt width    Max 999.9 mm/R        Belt mass    Max 999.9 g/m        Precision    ±1HZ100HZ        Digital sampling accuracy    < 1%        Display accuracy    & 22303;1Hz        Overall accuracy    < 5%        Operating temperature    +10° C~ +50° C        Transport temperature    -5 ° C~-70° C        Display    LCD        Measurement unit    Hz/N        Power supply    4×1.5V AAA        Housing    Plastic(ABS)        Dimensions    140mmx7mm2x34mm        Package size    248mmx206mmx52mm        Standard Accessories    Main Unit (one)            Operating Instructions (one copy)