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Belt Tension Meter - Type 3

The Type 3 Optical Belt Meter  has the capability to measure belt tension frequency from 7Hz to 300Hz and is supplied with an optical head, which is optimised for the best performance at low frequencies.  This belt meter is operated by a simple ON/OFF keypad button.

The optical sensor head uses an infrared beam to detect the vibration of the belt.  It is particularly suitable for small belts under low levers of tension.  This meter is useful for wide belts with large spans.  The sensor head is connected to the meter using the same sockets as the acoustic sensor.  As with the acoustic sensor the belt must be tapped to induce the natural frequency of vibration.  For very low frequency operation (below 20Hz) we recommend the use of the optical sensor head.  The sensor may be beamed onto the flat side of the belt (either the outer faces or pulley contact face) from distances of 5-15mm although in most cases readings may be taken from distances up to 50mm.  Alternatively, the edge of the belt may be used, with the depth finger on the sensor head providing an easy way to hold the sensor steady.

The sensor head MUST be held very steady when trying to measure low frequency belts.  This is to ensure that the belt vibration signal is not confused with signals caused by the hand of the operator shaking the sensor head.  The sensor must not be allowed to touch the belt, as this will prevent the belt from vibrating so that a tension reading cannot be taken.

As the meter requires 12 cycles of vibration to determine the belt vibration frequency, the meter will take 2 seconds to determine the frequency of a belt vibrating at 7Hz.  Therefore, it is important to allow time for the meter to register a reading.

A specialised version of 4Hz-300Hz is available by request.

Every CLAVIS meter is supplied with a precision mechanical resonator (tuning fork) for simple calibration validation by the user.  If you have additional calibration requirements CLAVIS can supply a Sonic Calibration Meter.  Read more about calibration...

You can expect each device to have the following;

  • CLAVIS Patented Sensor
  • Carrying Case
  • Tuning Fork (Checking Calibration)
  • Calibration Certification
  • Battery Charger
  • Rechargeable Batteries

Technical Specifications

Measurement Range
Frequency Range 7 to 300Hz
Measurement Accuracy
Below 100Hz +/- 1 significant digit
Above 100Hz +/- 1%
Environment Conditions
Operating Temperature +10℃ to +50℃
+50℉ to +122℉
Shipment & Storage Temperature +5℃ to +70℃
+23℉ to +158℉
Protection Class IP54
Type Infrared Optical
IR Wavelength 970mm
Visible Aiming Beam Narrow angle orange LED
Housing Machined aluminium
Cable length 1m
Power Supply
Battery Type AA (1.5V) Alkaline only
Number 4
Expected life 20 hrs
Compartment Location Back of meter
Optional Rechargeable Batteries
Battery Type AA (1300 mAh minimum)
Charger 12 to 15 V DC output
Socket/polarity 3.5mm positive centre
Physical Measurements
Height 185mm
Width 100mm
Depth (Top) 45mm
Depth (Bottom) 36mm


Enquiry Form

Thank you for your interest in CLAVIS.  Please use this form if you have any questions about our products and we'll get back to as soon as we can, or call us on + 44 (191) 262 7869.

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