How to read the hygrometer on the watch dial?
The co-branded watch Bioceramic Scuba Fifty Fathoms jointly launched by Blancpain and Swatch has been very popular recently. There are many versions and designs of Fifty Fathoms, one of the most classic is the Fifty Fathoms with hygrometer design.
Hygrometers were designed for professional diving in the 1950s. The hygrometer was originally added by Blancpain at the request of the U.S. Navy, so that Navy divers could judge at a glance whether the watch was in a normal waterproof state, and also to monitor the air tightness and damage of the watch at the first time, ensuring that Safety in underwater operations.
There is a circular humidity indicator at 6 o'clock on the dial. The color change of the indicator can be used to confirm whether water or moisture has entered the watch. The principle is that special synthetic chemicals react with water vapor to change color.
The white area in the upper half of the dial is the filling area of the humidity sensing material, which will react with water vapor and change color. The colored area in the lower half is the reference area. If the lower part is gray-blue, then the discoloration is gray-blue. In the same way, if the lower part is red, the color change will be red.
In the last century, many humidity indicating materials contained cobalt chloride, so used watches have certain risks.
However, the 2004 EU environmental regulations (2004/73/EC) have classified cobalt chloride as a Class II carcinogen. Therefore, there is no need to worry about the risk of chemical damage for humidity indicating materials after 2004.
