8 Checks, Adjustments, Calibrations
E15IB001EN-N
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8 Checks, Adjustments, Calibrations
8.1 Checks
1. Select
Checks
in the menu, then select one
of the already defined checks (or define a new
one by tapping
).
2. To edit the check parameters, tap
.
You can define checks for virtually any measur-
ing quantity available on the instrument.
a. Edit the parameters as appropriate.
For a
water check
or
air check
select as
follows:
- target type: “Quantity”
- target quantity: “Water density” or “Air
Density”, respectively
For a
custom check
select:
- target type: “Constant”
and specify a target value to be tested with
the check.
b. Also specify max. upper and lower deviation
and the correct temperature for the check.
c. Save the settings.
3. Observe all hints on the screen and fill the
check medium.
- For a
water check
, use freshly degassed
ultra-pure water.
- For an
air check
, clean and dry the measur-
ing cell thoroughly.
Use the camera image to check that the measur-
ing cell is clean or that water has been filled
bubble-free.
4. Tap
START CHECK
.
5. The summary of the check will show the check
results and a recommendation if the check has
failed and an adjustment is necessary.
IMPORTANT:
We advise you to follow the recom-
mendations.
All results are also saved in the data memory.
6. Tap
DONE
to close the summary.
If the water check has failed
We recommend taking corrective actions until the
check is valid again:
• Examine the camera image included in the
results to check that the water has been filled
bubble-free.
• Check the quality of the water.
• Clean the measuring cell thoroughly.
• If above actions do not help, perform an
air/water adjustment.
8.2 Adjustments
With an adjustment, a sample of exactly known
measurement properties (standard) is measured,
and the instrument constants are adjusted in a way
that the instrument delivers the known correct
results.
The instrument features a 2-point adjustment
(air/water adjustment) and a wide range adjustment.
DMA 1001 also features a 1-point adjustment
(water adjustment) as the standard adjustment.
DMA 1001:
After ten 1-point adjustments you are
prompted to perform a 2-point adjustment for
accuracy reasons.
• Perform a density adjustment if a check has
failed and corrective actions have not helped.
• We recommend an air/water density adjustment
if you relocate the instrument to a place where
the ambient temperature differs by more than
10 °C (18 °F).
•
DMA 1001 only:
To achieve highest accuracy,
we recommend to perform an air/water density
adjustment after each temperature change (one
hour after the required temperature has been
reached).
• You will likely never need a wide range adjust-
ment. Be aware that it will last several hours.
However, a wide range adjustment may be
useful when you adjust your instrument at a
temperature in the middle of the range, and if
subsequent measurements are out of specifica-
tions at other temperatures.
Table 2: Factory settings for max. deviations
(density)
DMA 501:
0.001 g/cm
3
DMA 1001:
0.0002 g/cm
3
