4.2 Weighing Method; 4.2.1 Absolute Weighing (Fast Method); 4.2.2 Substitution Method - Sartorius YP50K Betriebsanleitung

4.2 Weighing Method

4.2.1 Absolute Weighing (fast method)

The following schematic (Figure 2) shows the method. Reference
weighing takes place with a final zero point check in each case.
The zero point drift is determined in this way. Due to the high
resolution of the balance, zero point drift is always possible
as a result of the smallest changes in air pressure, temperature
or relative humidity. By ensuring that the intervals between the
Figure 2: Method for absolute weighing and the elimination of zero point drift

4.2.2 Substitution Method

In the substitution method, the mass of the Pycnometer is sub-
stituted by reference weights whose nominal mass corresponds
to the expected mass of the Pycnometer (Figure 3). In the case
of double substitution, each substitution cycle consists of four
readings on loading and unloading are short and even, the
respective zero point drift at the time of the weighing can easily
be determined and the measurement values can be corrected
accordingly. In this way the Pycnometer is provided with drift-
adjusted weight values from which the mass values m
result.
weighing operations. The substitution cycles with four
measurements in each case provide the cycle differences. Finally,
the mass of the Pycnometer can be calculated from the cycle
differences and the known mass value of the reference weight.
/ m
0 1
7