The Certina 230 is a typical representative of the small ladies' form watch
movement of 5 1/4 lignes, which were extensively used in the 1940ies and 50ies.
This movement, also known as Grana 230 and K.F.230 in literature,
impresses by its high quality, technically as well as visually.
The construction of the Certina 230 is typical for a swiss pallet lever movement.
The screw balance is secured in an Incabloc shock protecting bearing, which
was very modern at that time. The effective length of the hairspring can be regulated by a long
regulator arm on a golden-toned scale. A first visual highlight is the circle finish below
the balance.
wheel work
The pallet lever controls the movement, which is constructed the usual way with
escapement wheel, fourth wheel, third wheel and second wheel.
As you can see, there's a lot of space of the balance and mainspring barrel, which leads
to better precision and longer power reserve.
main plate
On the dial side, you immideatly spot the circle decoration - a good indicator for movements
of better-than-average quality.
Of course, the Certina 230 uses a yoke winding system, here with a setting lever
spring, that contains two holes.
The balance is shock protected on the dial side, too, but it's uncertain, which type of
shock protection is used here.
dial side view
Technical data
Manufacturer
Certina
Caliber
230
Number of jewels
17
Escapement
Anchor with pallets
Balance
Nickel screw balance
Shock protection(s)
Incabloc
Balance cock direction
counterclockwise
Hairspring stud
fixed
Regulator type
Long regulator arm
Movement construction
Fork Escapement wheel, Fourth wheel, Third wheel, Center wheel Mainspring barrel
Construction type
solid construction
Bridge shape
Shoe, curved, straight bottom, 4 gears
Winding mechanism
yoke
Setting lever spring
2 holes
Functions
Hour, minute
Beats per hour
18000
Size
51/4''' (measured: 12,8 x 19 mm)
Image in Flume Werksucher
1947 119
Factsheet
Test Results
The movement came in fair condition into the laboratory, but since the
watch built around it was in a bad condition (crystal missing, dial dirty), it
got a full service nevertheless.
Timegrapher Protocol
On the timegrapher, which was set into double precision mode, it showed
a good performance, especially, when you take into account, that this movement
is about 55 years old. It shows a very low bear error (indicatable
by very small lines on the printout). The assemblers at the Certina factory did
an outstanding job there!
The deviations are really OK, the two big numbers at "3 up" and "9 up" will
neutralize themselves on wearing the watch.
For a movement of that tiny size, the timegrapher results are really good and
prove the high quality of the Certina 230.
dial down
dial up
12 up
3 up
6 up
9 up
Measured Values
horizontal positions
dial down
+13 seconds/day
dial up
-8 seconds/day
vertical positions
12 up
+5 seconds/day
3 up
-20 seconds/day
6 up
+1 seconds/day
9 up
+30 seconds/day
timegrapher measurings
The power reserve was 43 hours - a very good value.
