The new BTM-400PLUS Belt Tension Meter or Sonic Tension Meter accurately measures the static tension of flat, V and ribbed belts of rubber, leather, fabric and composite materials by measuring the natural frequency (Hz) of a segment of the belt that has been tapped and then converting it into tension units of newtons (N) or pounds force (lbf).
The instrument uses a pulsed ruby red light source to measure the natural frequency of the vibrating belt. Unlike competitive models, the BTM-400PLUS is NOT affected by ambient noise, providing quick reliable results in all production and field applications.
Typical Applications External Probe Dimensions
**Static tension (T) accuracy depends on the precision of entered values for free belt span (L), density (d) and natural frequency (f) of the vibrating free belt span, that has been plucked or struck, as noted in the relationship: T = 4dL2f2. Note that highest accuracy is achieved in the frequency mode where readings are accurate to <1%, ± 1 Hz.
***Sensing distance can be extended when ambient light level is low also by adding a piece of reflective tape in the "target area" of the belt.