Automatic Level B2
Preface
Sokkisha’s history is the history of an automatic level.
The famous level B2 made to grow up and be bigger Sokkisha.
Sokkisha was organized at 1920 and the first production was Gurley type Y level.
After the second war , Sokkisha restarted to product instruments soon, but there are no record
of what production. The production of 4’ or 5’ transit or Y level were supposed.
And other , a magnetometer might be produced as same as before the war.
This is the seed of succeed of an automatic level. It is a very strange thing in the world.
The history of an automatic Level.
Sokkisha released B2 at 1963. The born course and technology are introduced on this paper.
The theory of an automatic level is given on other paper.
The first automatic level Ni2 was invented and released by Carl Zeiss in 1950.
Dr. Tsubokawa introduced Sokkisha the idea at 1951 and Sokikisha developed it as
named AL1 as early as 1952. As follows , the improved AL2 released at 1955. But the
function of ALx is not good. Because an air damper is applied to damp a pendulum and
the angle magnification is 2 , the image is moving , waving and not stable , and yes the
pendulum wire broke off very often. It is difficult to make up an good air damper in this
time by Sokkisha. It is needed to have very precious machining technology.
The developing of B2 (Iizuka history)
A man, named Mr. Iizuka was in Sokkisha
He was the manager of the technology department of Sokkisha.
He had an inspiration that an instrument of level shall be automatic in the future.
So , he thought and suffered how to make a good damper and a strong wire for the compensator.
At the time an idea flashed into his brain. How is a magnetic damper. This is not needed
a precious machining technology because no narrow air gap. He said that little thought
of the magnetometer technology may be in his brain.
At once , he made the sample and tested. But the function disappointed him, so the damping
capability was too weak on a wide gap as result the image was not stable at all.
He researched and investigated the magnetic damper theory. And he discovered
a concentrated magnetize effect ; not uniformed magnetized field is very effective for damping.
However it is so complicated to make that magnetized magnet and he researched and developed
with the maker, it was succeeded to make a rectangular shape magnet to be magnetized on the
corner. And as the result , the damping specification became best. The image was completely
stopped. He felt consciously his tear.
Improved compensator
Next challenge was to develop a thin and strong wire which is non magnetic. He chose
a stainless steel string as material.
The string was pressed and stretched to get a thin ribbon tape to be too
strong and no stress. So he also developed the specific tool to do them.
After that he tested how much strong it has. He dropped the instrument from 1m height.
The case was little broken but the instrument kept the function and accuracy.
Until to get this , he spent also 2 years.
A develop is accomoplished by the result of efforts and miracles.
Do you believe the God----?
Further -More
1. Damping Plate
An automatic level has a any pendulum which consist an optical system and damping frame.
The damping frame is a air damper , oil damper or magnetic damper. The plate is made normally
with a cupper plate in a magnetic system. But the cupper plate must be pure , certainly
nonmagnetic , but a pure cupper plate is so flexible , it isn’t used.
A hard cupper plate has mixed something. So we have to check non magnetic plate.
In this case Sokkisha was very merit because Sokkisha was making many kind of
magnetometers from many years ago. Sokkisha had the know how for magnetic knowledge.
Sokkisha had been able to select the best suitable plate.
2. Angle magnification
When a level slant by α, it is compensated with 2α by the pendulum. In this case ,
the position of the pendulum is set at the half position of a focus length.
It call two angle magnification. It is available to get more angle mag. by using
a optical design on the pendulum, example five.
In the case , the pendulum set at 1/5 of the focus length.
The merit of a large angle mag. is more sensitive to compensate and the size of
level is expected to be small.
Resolution
The total production number of B2 and other automatic levels may be over one million sets.
All levels use the magnetic damper system on the compensator.
This contributed Sokkisha the growth and expansion.
It is not exceeded that B2 equal Sokkisha. or Sokkisha equal B2.
The God helps a person making effort and studing.
B2 Optical design
Ni002 made by Carl Zeiss Jena. An ideal auto theory of auto level is applied.
