A quartz crystal chronometer is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than mechanical clocks.
- This is fast replacing the winding type chronometer
- It is completely solid state and crystal controlled.
- The rate is fairly stable
- Light and easy to carry
- Sealed to resist entry of dust and spray. Undergoes stringent tests for shock, vibration and extremes of temperature
- Quartz Chronometer (QC) is normally powered by a 5 volt, leak-proof AA alkaline with an average life of one year, the battery condition is shown by a indicator..
- QC is usually in analogue form with either 12 or 24hrs graduated dials.
- Digital readout displays are not popular as it is felt that they do not allow exact noting of time
- The seconds hand is made to move in 1 second jumps so that exact time can be read.
- Some old models may be powered by ships mains supply with a battery backup
- Some chronometer use a test socket arrangement
What is principle of operations of Quartz Crystal Chronometer?
- The aim is to achieve a steady frequency of 1Hz, which signifies one second per cycle.
- When electric impulses are passed through quartz crystal, the crystal oscillates.
- If the frequency of the electric impulse is adjusted to equal the oscillation of the crystal, resonance is achieved.
- The frequency of the crystal may be around 10 KHz or more
- This is converted into low frequency pulses of 1 Hz through a step by step dividers
- The final 1 Hz impulses pass through a control unit and move the seconds hand of the chronometer by low power and very small pulse length.
- The accuracy of the oscillations depends upon the quality of the crystal and variation of temperature.
What are different controls of Chronometer?
The controls, which are normally located behind the chronometer, vary with different models, but the basic functions are as follows: