The Citizen Miyota 8215 is a robust automatic movement manufactured by Citizen Miyota in Japan for a few decades now, having had its debut in 1977.
It is a non adjusted 21 jewels movement beating at 21600 bph or 3Hz (6 half-cycles per second).
Its seconds hand are powered via a indirect drive which means that the Miyota 8215 automatic movement does not hack its seconds hand when setting time and the seconds hand may stutter if watch movement is subject to a harsh move.
However the indirect seconds hand drive does not affect the accuracy or durability of the watch movement.
Citizen Miyota has developed in 1956 a proprietary shock resistance technology called parashock used till this day in many of their movements as in the Miyota 8215.
The auto winding mechanism of the Miyota 8215 is unidirectional and charges the spring barrel when rotor moves counter clockwise (also indicated in engraved arrow in rotor).
The movement has a power reserve of about 42 hours and its daily accuracy is of about -20 to +40 seconds per day. The date setting mechanism also has a quick set mode as found in majority of modern mechanical watch movements. The hands size of the Miyota 8215 movement are 170 / 100 / 15.2.
Citizen Miyota 8215 Technical Drawing:
Citizen Miyota 8215 Technical Details:
|Type of movement||Automatic movement|
|Date Wheel||Yes (usual setup – date wheel at 3 o’clock with white disc, black font)|
|Number of jewels||21|
|Power Reserve||Approximately 42 hours|
|BPH (Frequency per Hour)||21 600 bph or 3Hz|
|Hands Size||170 / 100 / 15.2|
|Balance Staff||Citizen 039-1020
balance with hairspring