AMPLITUDE

The measure of the amount of rotation in the swing of the balance wheel, in either direction, is usually expressed in degrees. In a running watch, the balance wheel swings or rotates clockwise and counterclockwise. Each swing in either direction is called a “beat”. Amplitude is the number of degrees of rotation of the beat. Amplitude is higher, typically in the range of about 270 to 315 degrees, when a watch is lying flat or in the “dial up” or “dial down” position. Amplitude usually falls when the watch is in a vertical position, primarily due to increased friction. Amplitude can also fall as the watch winds down and the mainspring delivers less power. The amplitude that is too high or too low, or that changes too much in different positions, can indicate a problem with the movement.

Clock & Watch Encyclopedia

A

A/h or ALTERATIONS (or ALTERNANCE) PER HOUR
AMPLITUDE
ANA-DIGI
ANALOG
ANCHOR ESCAPEMENT
ANGLAGE
ANNUAL CALENDAR
ANTIMAGNETIC
APPLIED INDICES
AUTOMATIC MOVEMENT

B

BALANCE
BREGUET OVERCOIL HAIRSPRING

C

CALENDER
CALIBER
CHAPTER RING
CHARGE INDICATOR
CHRONOGRAPH
CHRONOMETER
COLUMN WHEEL
COMPLICATION
COSC (OR C.O.S.C.)
CROWN
CRYSTAL

D

DIAL
DIGITAL
DISPLAY

E

EIGHT-DAY MOVEMENT
ELECTRONIC
EQUATION OF TIME
ESCAPEMENT

F

FINE ADJUSTMENT
FLYBACK CHRONOGRAPH
FREQUENCY
FUNCTION

G

GENEVA SEAL
GENEVA WAVES
GMT
GRANDE COMPLICATION
GUILLOCHE

H

HACK, HACKING SECONDS
HAIRSPRING
HALLMARK
HAND-WOUND MOVEMENT
HOROLOGY

I

INCABLOC
INDEX

J

JEWELS

K

KARAT

L

LEVER ESCAPEMENT
LIGNE
LIMITED-EDITION WATCH

M

MAINSPRING
MANUAL-WIND MOVEMENT
MANUFACTURE
MECHANICAL WATCH
MICRO-ROTOR
MINUTE REPEATER
MOON-PHASE DISPLAY
MOTION WORK
MOVEMENT

O

OSCILLATION

P

PALLET
PERLAGE
PERPETUAL CALENDAR
PERPETUAL DAY/DATE
PLATE
POWER RESERVE
POWER-RESERVE INDICATOR

Q

QUARTZ WATCH

R

RADIO-CONTROLLED
RATTRAPANTE
REGULATION
REPEATER
RETROGRADE DISPLAY
ROTATING BEZEL
ROTOR

S

SCALE
SCREW-DOWN CROWN
SELF-COMPENSATING HAIRSPRING
SHOCK ABSORPTION
SKELETONIZED MOVEMENT
STOP-SECONDS FUNCTION
SUBSIDIARY DIAL
SWISS MADE

T

TANTALUM
TITANIUM
TACHYMETER
TOURBILLON
TRIPLE DATE
TRITIUM

V

VIBRATION or VPH

W

WATER-RESISTANT
WHEEL TRAIN
WORLD TIME WATCH