12 5.2 Absolute Weighing Method; 12 5.3 Substitution Method - Sartorius YP50K Betriebsanleitung

5.2 Absolute Weighing Method
Weighing sequence with the test specimen:
– Place the test specimen in the centre of the Pycnometer and fill
with the reference fluid.
– Check the constancy and distribution of the temperature in the
Pycnometer.
– When stable, measure the temperature at two insertion depths
and calculate the mean value.
– Calibrate the balance and prepare it for measurement.
– Measure barometric pressure, ambient temperature and relative
humidity.
– Load and unload the balance several times with the Pycnometer.
– Carry out a series of at least 6 weighing operations. Proceed as
follows in each case:
§ Set the unloaded balance to zero and record the time.
§ Place the Pycnometer in the centre of the balance.
§ After stabilisation and the specified waiting time, take the
measurement and record the time.
§ Unload the balance immediately.
§ After the same time has elapsed as when loading, carry out
the zero point check and take the measurement.
§ Unload the balance.
§ Eliminate zero point drift.
– Calculate the weight value I
– Remove the test specimen.
Weighing sequence without the test specimen:
– Fill the Pycnometer with the reference fluid only.
– Re-check the constancy and distribution of the temperature in
the Pycnometer.
– When stable, measure the temperature at two insertion depths
and calculate the mean value.
– Check the barometric pressure, ambient temperature and relative
humidity (ideally the values should not have changed).
– Carry out a further series of at least 6 weighing operations.
Proceed as described above for the test specimen.
– Calculate the weight value I
12
(drift-adjusted mean value).
1
(drift-adjusted mean value).
0
5.3 Substitution Method
Weighing sequence with the test specimen:
– Place the test specimen in the centre of the Pycnometer and fill
with the reference fluid.
– Prepare the reference weights.
– Check the constancy and distribution of the temperature in the
Pycnometer.
– When stable, measure the temperature at two insertion depths
and calculate the mean value.
– Calibrate the balance and prepare it for measurement.
– Measure barometric pressure, ambient temperature and relative
humidity.
– Load and unload the balance several times with the Pycnometer
and the substitution weights.
– Carry out a series of at least 3 substitution cycles.
Proceed as follows in each case:
§ Load the balance with the substitution reference weights and
record the time.
§ After stabilization and the specified waiting time, take the
measurement.
§ Quickly remove the reference weights.
§ Place the Pycnometer in the centre of the balance and record
the time.
§ After stabilization and the specified waiting time, take the
measurement.
§ Unload the balance immediately.
§ Place the Pycnometer back on the balance and record the time.
§ After stabilization and the specified waiting time, take the
measurement.
§ Unload the balance again immediately.
§ At the end of the cycle, re-load the balance with the
substitution reference weights and record the time.
§ After stabilization and the specified waiting time, take the
last measurement of the cycle.
– Calculate the weight value I
– Unload the balance.
Weighing sequence without the test specimen:
– The method is the same as for the weighing sequence with the
test specimen
– Calculate the weight value I
– ∆ I (drift-adjusted mean value).
1 1
– ∆ I (drift-adjusted mean value).
0 0