BTM-400PLUS Belt Tension Meter

Supplied with both plug-in and cable-connected sensors

The CHECK-LINE® BTM-400PLUS 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.


  • Includes two (2) separate Sensors – a plug-in type for one-handed operation and a cable-connected type for measuring belts with limited access space
  • Compact, easy-to-use design
  • Readings unaffected by nearby magnetic fields or noise
  • Displays tension in newtons (N) or pounds force (lbf) or natural frequency in Hertz (Hz) - selectable
  • Displays Menu in English, German, Spanish, Portuguese, French or Italian & others - selectable

Complete Kit

The BTM-400PLUS is supplied as a complete kit, including:
- BTM-400PLUS belt tension meter
- plug-in sensor
- cable connected sensor
- 9-volt battery
- instruction manual
- delivered in a foam-fitted, hard plastic carrying case.
Kit-126141 BTM-400PLUS


Measuring Range*
10 - 400 Hz (and higher)
± 5% or better
ABS Plastic
2 line LCD, 16 characters per line
Input Range
free span length: up to 9.990 m
belt mass: up to 9.999 kg/m
Power Supply:
9V battery
Calibration Certificate
Input ranges:
Free stand length: up to 9.99 m
Belt mass: up to 9.999 kg/m
Temperature Ranges:
Operation: +10 °C ... 50 °C
Transport: -5 °C ... +50 °C
Air humidity
85% RH, max.
Plastic (ABS)
126 x 80 x 37 (LxWxH)
Weight net (gross)
Approx. 170 g (approx. 660 g)
2 years

Typical Applications

Typical Applications

Buy Now


Item           Product name Price  
Belt Tension Meter € 635.00
* All mentioned prices are excluding VAT & excluding shipment.
Availability: Available , preorder 1-2 weeks , special order, request

External Probe Dimensions

probe dimensions

*BTM-400PLUS can measure up to 800 Hz, however most belts will break near 400Hz

**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.