Pic GRAIN 17
Complete grain tester
scale, Germany. The complete tester include:
A - measuring bucket
B - striking knife
C - suction cylinder
D - filling pipe
E - discharge cylinder
F - scale beam
G - weighted hanger
H - brass stand for the beam
The weights ( common
knobbed weights ) are lost.
Weighing grain today is a complicated business, but it was not always so.
A long time ago, it was realized that buying grain by volume, like wine or
milk, was inadequate. The usefulness of grain varied with the size of the
seeds, their moisture content, the amount of dirt included, and the damage
done by worms which hollowed-out the husks. Thus it was found necessary to
weigh the grain in addition to measuring its volume. Rather than weighing
all the grain, samples were taken from each sack, and tested for quality.
Using ordinary measures and scales, many imperfections were present.
Inconsistencies in the capacity of the measures, and the different weights
used in each town and country, made comparison difficult. Also, the
density of grain put into the measure varied from user to user, according
to his method of doing lt.
Recognizing these difficulties, the instrument-maker Gniser, Inspector for
Berlin, introduced improvements for weighing grain, in 1781. He fixed
standards for the whole of Germany, using the volume measure 1/8 Metze of
Berlin (1/128 Scheffel), and the weight of 1 Krampfund, also of Berlin. In
order to have the same density of grain in the measure, he used a funnel
with a variable diameter nozzle, which was adjusted to suit the type of
grain being tested. He also specified the distance between the funnel and
the measure, and the time taken to fill lt.
Gniser noted that imperfections still arose because the weights were
subjected to damage and wear, when they were dropped into the scale
bucket, or when they were carried about by the grain merchants. But it was
well over a century before further improvements were made, in 1912, when a
20 liter grain tester was admitted for verification in Berlin. This
apparatus replaced the weight bucket with a hanger and slotted weights,
and an improved method of filling was provided.
However, the 20 liter capacity proved to be too large for convenience, and
after a few years, a 1/4 liter capacity was adopted. The cost of sending
1/4 L samples by post, was much cheaper for the merchants, hut it was much
less accurate, so a 1 liter capacity also developed.
This system was used for some years, and then in 1937/38, the dimensions
of each part of the tester, and especially of the capacity measure, were
fixed. These specifications are still legal, and in use today.
Now to use
a German Empire Grain tester
Now, a short description of the weighing procedure, mainly derived from
the instructions given in the book of conversion tables:
"Amtliche Tafeln fur Getreideprobier mit Vorlaufkorper Bauarten bis
These tables show the weight of a Hectoliter (100 L) of grain against the
measured weight of the sample.
The corn to be tested must be at room temperature, and air dried. During
measurement the humidity must be between 50 and 75%. The grain tester, is
set up on a strong horizontal table or bench, then the striking knife is
inserted into the slot in the bucket. The suction cylinder is placed on
top of the knife, and the filling pipe fixed to the top of the bucket.
The bulk density of the grain depends upon the quantity used, and how the
filling pipe is filled. For this reason, the discharge cylinder must be
filled only to the prescribed mark, and the use of a funnel is not
permitted. The discharge cylinder is filled from the sack of grain, and
then held 3 to 4 cm from the filling pipe. Grain is poured into the pipe
steadily and to the middle, so that the grain will not touch the walls.
The pouring time for a 1 L tester in about 12 seconds, and for a 1/4 L
tester, about 8 seconds. (The discharge cylinder should be filled in the
Then the striking knife is pulled out quickly., without moving the bucket.
The suction cylinder falls rapidly and creates a vacuum which causes the
grain to follow and settle consistently, each time the tester is used.
Holes are provided in the bottom of the bucket to release the air trapped
below the cylinder.
At this stage, the striking knife is put beak into the slot, the excess
grain is tipped out, and then the knife and filler pipe are removed. Now,
the bucket is suspended from the scale and weighed to an accuracy of 0.5
Opposite the measured weight, in the conversion tables, the corresponding
weight for a Hectoliter is found. Each type of grain has its optimum
weight. If it is lighter or heavier than the Optimum, the utilization
factor is poorer and the price is correspondingly lower.
Schmidt (EQM Autumn 1978 )