A device (1) for measuring a relative humidity level inside the enclosure (9) of a case (3) of a watch (2), the device (1) including: an emitter module (5) provided with a source of light radiation capable of emitting light beams (8) towards the enclosure (9) of the case (3); a receiver module (6a, 6b, 6c) for receiving at least one acoustic signal (12) from the enclosure (9), and a control unit (7) connected to the modules (5, 6) and which is configured to evaluate the water vapour content of a gaseous fluid (11) contained inside the enclosure (9) as a function of the at least one acoustic signal (12) received by the receiver module (6a, 6b, 6c).

Method of assembling a timepiece comprising a watch movement and a water-resistant case, the method comprising: a first stage of closing the case by fitting and securing a first case element, more particularly a back, and then a second stage of closing the case by actuation of a second case element, more particularly a stem, in particular a winding stem or a valve stem or a push-button stem, the second case element being mobile between a first configuration, in which a fluid communication between the interior of the case and an environment outside the case is permitted, and a second configuration, in which the fluid communication between the interior of the case and the environment outside the case is limited, the second stage of closing being an actuation of the passage of the second element from the first configuration to the second configuration.

An assembly (1) for measuring a relative humidity level inside a watch (2), comprising the watch (2) and a device (4) for determining the humidity level present in the enclosure (9) of a case (3) of this watch (2), the determination device (4) comprising a free space optical system and a control unit (7). The system includes: an emitter module (5) for emitting at least one light beam (8); and a receiver module (6) for receiving the at least one light beam (8); the control unit (7) being connected to the modules (5, 6) and the at least one light beam (8) emitted by the emitter module (5) defining an optical path partly comprised in the case (3) and extending as far as the receiver module (6) and the control unit (7) being configured to evaluate the absorption of the light beam (8) by the water vapour capable of being present inside the enclosure (9) of the case (3).

Method for testing the water resistance of at least one timepiece, wherein it comprises the following stages: E1Measuring the rate of the timepiece when subjected to a first external pressure, in particular atmospheric pressure, in order to obtain a first reference rate value; E2Measuring the rate of a timepiece when subjected to a second external pressure inside a pressurization chamber, in order to obtain a second rate value under pressure; E3Comparing the rate value under pressure and the reference rate value in order to deduce therefrom the presence or otherwise of a deficiency in the water resistance in the event of a variation in excess of a predefined threshold.

A device for measuring the humidity in the internal volume of a case of a watch, which device includes a watch including a case housing an optical system, the optical system including a transmitter transmitting a light beam, a multi-pass cell through which the light beam is intended to pass, and a receiver intended to receive the light beam once it has passed through the multi-pass cell; a management module external to the case, including a processing unit configured to communicate with the optical system and to process data transmitted thereby in order to determine the humidity present in the internal volume of the case on the basis of the absorption of the light beam by the water vapour that may be present in the internal volume of the case.

Method for testing the water resistance of at least one timepiece, wherein it comprises the following stages:

E1Measuring the rate of the timepiece when subjected to a first external pressure, in particular atmospheric pressure, in order to obtain a first reference rate value;

E2Measuring the rate of a timepiece when subjected to a second external pressure inside a pressurization chamber, in order to obtain a second rate value under pressure;

E3Comparing the rate value under pressure and the reference rate value in order to deduce therefrom the presence or otherwise of a deficiency in the water resistance in the event of a variation in excess of a predefined threshold.

A device for measuring the humidity in the internal volume of a case of a watch, which device includes a watch including a case housing an optical system, the optical system including a transmitter transmitting a light beam, a multi-pass cell through which the light beam is intended to pass, and a receiver intended to receive the light beam once it has passed through the multi-pass cell; a management module external to the case, including a processing unit configured to communicate with the optical system and to process data transmitted thereby in order to determine the humidity present in the internal volume of the case on the basis of the absorption of the light beam by the water vapour that may be present in the internal volume of the case.