Casella TBRG [100000E] 0.2 mm Non-Heated Tipping Bucket Rain Gauge. Casella TBRG is a reliable and extremely robust transducer, designed as a stand-alone sensor for operation with an existing logging system. The body and funnel are made from aluminium alloy with an accurately machined septum ring at the top giving an aperture of 400cm2. The tipping bucket mechanism is mounted inside the body on a cast aluminium-alloy base, incorporating a built-in spirit level to ease correct positioning. All this ensures the TBRG is quick and easy to deploy, whilst providing reliable operation with the minimum of maintenances.