11 Checking, Adjusting and Calibrating the Instrument
C76IB003EN-E
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2. Use a calibrated external pressure sensor to get an exact pressure value.
Do not use the atmospheric pressure that you can get from a local weather
station, because this usually is not the absolute atmospheric pressure, but a
calculated atmospheric pressure at sea level.
3. Tap <OK> to start the adjustment.
4. Enter the atmospheric pressure (in hPa) and tap <OK>.
5. Wait for the adjustment to be finished and then tap <OK>.
The final value may deviate from the one you entered by up to ±7 hPa. This
will not influence the measuring accuracy.
11.3.5
Performing Special Adjustments
11.3.5.1
Special Adjustments
Special adjustments are user-specific adjustments for special density units,
concentrations and temperatures. After a successful adjustment procedure, the
special adjustment can be used as a standard measuring quantity that is
displayed and printed. It can also be used:
•
as an input parameter for a user function
•
as the API input quantity
•
as the input quantity for the Canadian excise alcohol table
Five different special adjustments can be stored. For each special adjustment
name, unit and temperature can be specified.
During a special adjustment, density coefficients are calculated from the
oscillation period of two liquids of known density according to:
Prerequisites for standards
The densities of the two liquids that are used for special adjustment have to differ
by at least
Δρ
= 0.01 g/cm
3
.
The PQ-values of the adjustment media have to differ by at least 0.0001.
Special adjustments can be performed at any set temperature within the specified
temperature range (0 to 90 °C or 32 to 194 °F).
ρ
...... density
A, B .. density coefficients
PQ ... period of oscillation
ρ
A
PQ
2
B
–
×
=
