Temperature Measurement (TMT)

Read the temperature on a mechanical thermometer

The BALL TMT movement powers the world’s first mechanical thermometer from -35°C to 45°C (-31°F to 113°F) wristwatch. It uses a spiral bimetallic thermometer to measure temperature with far more accuracy than temperature modules used in past watches.

The design obstacles

At BALL Watch Company, the most difficult technical challenge our researchers faced in the mechanical thermometer (TMT) watch project was that the height of the entire movement module must be just 5.1mm. The tight coil must fit perfectly into the workings of the automatic movement. Our master watchmakers have overcome many design obstacles such as the height of the bimetallic spring, the height and milling of the main plate and bridge.


The mechanism's prowess

We invented a unique system of fine regulation using a patented fine regulating screw that does not block the bimetallic blade. The role of the fine regulating screw is, on the one hand, to precisely adjust the position of the temperature indicator, and on the other hand to hold the bimetallic spiral at its extremity. After fitting a hand on the axe of the thermometer, we test the measurement and control its vibrations. Finally, we conduct rigorous shock tests to ensure shock resistance.

Sign up to hear about the latest news and exclusive products
Male  Female 
  SIGN UP