Calibration Intervals; 1-Point And Multi-Point Calibration; Reference Temperature; Temperature Coefficient - Dostmann pH 7+ Manual Del Usuario

Calibration intervals

The meter is calibrated before leaving the factory and can generally be used right out of the box.
•
• Normally perform calibration per month.
For high accuracy measurements or large temperature deviation from the reference temperature (25°C),
•
perform calibration per week.
• Use conductivity standard solution to check whether there is error. Perform calibration for large error.
For new electrode or factory default setting, perform 3-point or 4-point calibration. Choose closer
•
standard solution to the sample solution to perform 1- point or 2-point calibration. For example: 1413
μS/cm standard solution is suited for range 0-2,000 μS/cm.

1-point and multi-point calibration

For 1-point calibration after 3-point or 4-point calibration, the previous calibration value in the same range will be
replaced, meanwhile, the meter will show the calibration guide icon of this point, other two calibration guide icons will
be deleted, but the chip will reserve the last calibration data. When choose multi-point calibration, perform calibration
from low to high concentration to avoid standard solution of low concentration being contaminated.

Reference temperature

Reference temperature of factory default is 25°C. Other reference temperature can also be set for range 15°C –
30°C. Select per parameter P2.5.

Temperature coefficient

The temperature compensation coefficient of the meter setting is 1.91%. However, the conductivity temperature
coefficient is different for solutions of a different variety and concentration. Set per parameter P2.6..
Note: When the coefficient for the temperature compensation is set to 0.00 (no compensation), the measurment value will be
based on the current temperature.
Solution
NaCl solution
5% NaOH solution
Dilute ammonia solution
10% hydrochloric acid solution
5% sulfuric acid solution

Avoid contamination of standard solution

Conductivity standard solution has no buffer. Please avoid being contaminated during usage. Submerge the electrode in
standard solution before wash the electrode and allow it dry. Please renew conductivity standard solution frequently
especially for standard solution of low concentration 84μS/cm. The contaminated standard solution can affect accuracy.
Temperature compensation coefficient
2.12%/°C
1.72%/°C
1.88%/°C
1.32%/°C
0.96%/°C
15
EN