Thermo Scientific Sarasota FD910, Руководство пользователя

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Calibration
Method 2: Off-Line Static Water Test
4-2
Sarasota FD910, FD950, & FD960 User Guide Thermo Fisher Scientific
Remove the unit from the line and clean it as described in Chapter 5. For
best results, perform the following test in a temperature controlled or
temperature stable room after the meter and water sample have been
allowed to stabilize to room conditions for 12 hours.
1. Close the density meter with a plug blanking the lower flange. Tip the
unit at a 45-degree angle and slowly pour distilled water, if available,
down the side of the tubes. This is to minimize the amount of air and
bubbles that may be trapped in the water during filling. Run a cleaning
brush that has never been used with anything but water through each
tube. This ensures that all bubbles are wiped from the tubes.
2. Allow the temperature to stabilize. Then record the density reading and
temperature obtained. Compare the density value with the water data
in Table 4–1.
If the reading is within ±1.0 kg/m
3
of the reading in the table, the
density meter is working correctly. If the reading is outside the limit, do
the test again carefully. Larger than expected uncertainties, mostly due
to air bubbles and thermal gradients, often occur while performing
static water tests. Do not expect static water tests to obtain as high a
degree of accuracy as the manufacturer’s calibration. If accuracy better
than ±1.0 kg/m
3
is required, return the density meter to the factory for
calibration. Unless the application is particularly severe, a one-year
calibration interval should be adequate.
Table 4–1.
Temperature ( ° C) Density (kg/m 3 )
10.0 999.7
15.0 999.1
20.0 998.2
25.0 997.0
Method 2: Off-
Line Static
Water Test