How A Water-Resistance Indicator Works

Posted by Richard Paige: TimeZone Forum

The water-resistance indicator, shown in the picture, is a metal capsule, which screws into the case of a water resitant watch. It contains about 7 mg of copper sulfate (CuS4), which serves to control and absorb moisture which could damage the mechanism. This innovative device thus avoids unnecessary water-resitant checks.

The water-resistance indicator ensures maximum watch reliability by guaranteeing a totally moisture proof environment within the watch case. The indicator absorbs the moisture within the case, thus prolonging the intervals of retesting the water-resistance of the case.

The water-resistance indicator’s color shows the amount of water absorbed…when the capsule reaches it’s total absorption capacity (3.9 mg of water), it turns deep blue, thus indicating that the wearer should now check for water resistance.

Only a few manufacturers use this device, due to the added cost of installing into the case.

Best regards,
Richard Paige