Interview with …
Konrad Schäfer, Managing director, Funke-Dr. N. Gerber Labortechnik GmbH, Berlin
Thank you Mr. Schäfer, for welcoming
FOOD-Lab International at the
Funke-Gerber Labortechnik headquarter
in Berlin. We would like to talk about
your latest developments. But let’s start
with a view into the company’s history.
It is my pleasure. Paul Funke has founded the
company in the year 1904 and everything
started with the butyrometric fat analysis.
The method had already been developed in
1894 by Dr. Niclaus Gerber. This method has
been quickly established in the market. Paul
Funke has improved the round butyrometer
a little and proposed the flat butyrometer
which has prevailed ever since. The original
round butyrometers as developed by Dr Gerber
are rarely applied.
Is it true that the butyrometric method is
the oldest method for milk testing in the
It is certainly one of the oldest methods.
Please explain to us the success of the
method over more than 100 years!
In comparison to the reference method by
Röse-Gottlieb it is quick, simple and easy-toread
off the scale.
How do you judge the handling safety?
Due to the nature of the material glass breakage
and other issues may occasionally occur.
However, these are manageable by proper
handling. The glass butyrometers can be used
for approximately 30-50 measurements. But
thereafter they may break easily, predominantly
due to high centrifugation
Now you are offering
a new product
We have developed
It will become unusable by scratches or
cloudiness over time. However it is unbreakable.
We do not have full experiences yet
but we are convinced that significantly more
measurements will be realised compared to
the glass butyrometers.
Are there other advantages beyond?
Each single glass butyrometer is individually
scaled or calibrated using mercury. PP-butyrometers
do not need to be calibrated individually
due to the manufacture by the injection
moulding process which ensures identical
quality of each butyrometer. Thereby, an
identical scale can be applied to each single
PP-butyrometer. Tolerances are much smaller
than on the glass butyrometers. The procedure
of pipetting in is practically identical.
When mixing milk with sulfuric acid and alcohol
an exothermic reaction with high heat
generation will result. Basically, this is similar
with both butyrometers. However, thermal
conductivity of PP is much lower leading to
a lower temperature of the PP butyrometer
after the mixing process so that there is
no risk of burns of hands. After withdrawal
from the water bath the PP butyrometer
will keep the temperature that is required
for correct read off for a longer time. A further
advantage is that the PP butyrometer
externally shows a flat neck, but the column
of fat is displayed and read off internally
from a round scale thus increasing the contrast.
Looking into a glass butyrometer from
above will show that it looks oval. Therefore
the column of fat is relatively thin implying
that the column of fat is significantly less visible
as in the PP butyrometer. The contrast
is therefore increased. In glass butyrometers
the zero point will be adjusted screwing
a patented rubber closure more or less