Abstract: In order to determine the adjustment precision .DELTA.T of a timepiece provided with an oscillator (1) and an adjustable frequency divider chain (3-18; 18-20) on which an adjustment unit (15) acts, initially the real period TQ of the oscillator is measured with the adjustment unit disconnected following a first actuation of a time setting circuit (21). A second actuation of said circuit then effects running of the display at a rate n times above the normal and the adjustment unit is connected. Following a time T/n representing the adjustment cycle the period TQ is measured as corrected by the amount n.DELTA.T, thus TQ+n.DELTA.T. The first measured value obtained is subtracted from the second thus giving n.DELTA.T which when divided by n gives the adjustment precision .DELTA.T.

Abstract: An apparatus for testing the gas impermeability of watch cases or other small articles comprises two enclosures. A bellows forms part of a hermetic separation between the enclosures, the bellows serving to move the movable plate of a variable condenser. The condenser is connected in an oscillator circuit to vary the oscillator frequency in accordance with the differential pressures between the two enclosures. The oscillator output frequency is compared with the output frequency of a stable frequency generator to provide a measurement indication. A watch case is placed within one enclosure and both enclosures brought to equal pressures after which the measurement of gas impermeability may begin.

Abstract: A method and apparatus for detection whether an input signal is periodic or aperiodic, wherein reference pulses at a constant frequency are added during a first interval determined by a number of cycles of the input signal and reference pulses at the same frequency are substracted during a second interval determined by an equal number of cycles of the input signal. If the input signal is periodic, the counting result is zero or nearly zero since the counting intervals have been of equal duration. If the input signal is aperiodic, the counting result differs from zero because the counting intervals have not been of equal duration.

Abstract: A balance wheel assembly includes a balance staff having a balance wheel hub, a saddle, a shoulder, a cylindrical portion to which the balance spring is attached, and a lower stem extending through a flange. The saddle and cylindrical portion are on the same side of the hub with the shoulder being on the opposite side of the hub and spacing the flange from the hub. The balance spring is attached directly to the cylindrical portion of the balance staff.