The Age reports that Europe's second largest bell, nicknamed Pummerinand weighing 21 tonnes, is one of several famous bells across Europe being checked to determine their life spans and unlock the secret of the optimum chime.
Using acceleration sensors and echo microphones, the sensor strips are like electro-cardiograms that determine the health of human hearts.
"The Pummerin is well," determines Mr Rupp, a project scientist and professor at the Polytechnic College in the German city of Kempten.
"We just want to know how long it can be healthy and if there is any risk she could crack like so many others."
Hamburg's Millennium Bell has already undergone the examination, and bells in the Notre Dame Cathedral in Paris and St Paul's Cathedral in London are lined up as the next patients.
The project was triggered by a debate 10 years ago among bell-makers who wanted to determine if bell clappers were hitting the right spot.
Every time a clapper hits, it causes a slight deformation and strains the metal. Experts say the location and force of the clapper's hit will have an impact. The sensors record how hard the hit is, how deformed the bell is, and its chime.
Dangers also lurk in modernisation, the experts say. Churches opting for mechanical or computerised systems over human ringers might shorten their bells' life span, some say.
"Many fear historic bells could be damaged severely or even destroyed by this new way of ringing," Mr Rupp says.
Time and technology take toll on bells (The Age, 30/4/07)
LINKS (not necessarily endorsed by Church Resources)
Official Website of St Stephen's Cathedral
St . Stephen's Cathedral, Vienna (Wikipedia)
1 May 2007