Applied Measurements

How to measure grip strength of an eagle for BBC Natural World

Product

Easily customised to measure 250kg force.

Tilly the golden eagle, courtesy of the BBC Natural World Series, Super Powered Eagles.

Last year, we were asked to design a sensor to measure the grip strength of a golden eagle named Tilly, for the award-winning BBC documentary series, Natural World.

Challenge – to find a load cell that could withstand the estimated grip strength of an eagle

As Tilly had been trained to catch and grip a tennis ball, the load cell needed to be small enough to fit inside a similar-sized measuring device yet withstand Tilly’s tremendous grip strength.

Thanks to their miniature design, our DBBSMM miniature S-beam load cells were ideal for the job.  Not only are they very compact but their s-shaped design offers superior side-load rejection and high accuracy.

5 reasons we chose the DBBSMM miniature S-beam load cell to measure grip strength

 

  • Easily customised to measure 250kg force

 

 

  • Compact only 35mm high – small enough to fit inside the tennis ball for Tilly to grip

 

 

  • High accuracy – Non-linearity <±0.03% of rated capacity

 

 

  • Extra sealing added to give outdoor IP65 protection rating

 

 

  • Superior side-load rejection

 

How was the S-beam load cell installed?

The DBBSMM miniature S-beam load sensor was fitted inside 2 halves of a metal pipe coupled with a T24-SA wireless strain gauge transmitter.  Once Tilly had gripped the tennis ball, the sensor and T24-SA would transmit data wirelessly to a T24 base station.  The T24-SA wireless acquisition module is able to transmit high-speed updates of 200 per second making it ideal for this application.

The data transmitted by the DBBSMM miniature S-beam load cell would be logged by the free downloadable T24LOG100 software.  Thanks to the T24LOG100 software, the results could be viewed in real-time and logged for later analysis.

Sadly, just before filming, our load cell looked so enticing that Tilly’s overwhelming curiosity led to her ripping the wires out of the load cell.  We’re not sure there’s an IP rating for birds of prey.

We were honoured to be a part of this fantastic programme and look forward to many more amazing BBC Natural World documentaries.

Super Powered Eagles can be watched on BBC iPlayer.

Products used:

DBBSMM miniature S-beam load cell

T24-SA wireless strain gauge transmitter

Thanks to: Mantracourt Electronics

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