XS 70 Serie Manual De Instrucciones página 25

P3.2 Calibration mode
Access this setup menu to select automatic or manual recognition of the standards for performing the
calibration:
AUTOMATIC : -default- the device automatically recognizes up to 3 of the following standards.

84 µS/cm, 147 µS/cm, 1413 µS/cm, 12.88 mS/cm e 111.8 mS/cm.
CUSTOM : the device can be calibrated on a point with a manually entered value.

Note: To obtain accurate results, it is advisable to calibrate the device with standards close to the
theoretical value of the solution to be analysed
P3.3 e P3.4 Temperature compensation in conductivity measurement is not to be confused with pH
compensation.
In a conductivity measurement, the value shown on the display is the conductivity calculated at

the reference temperature. Therefore, the effect of temperature on the sample is corrected.
 On the other hand, when measuring pH, the pH value at the displayed temperature is shown on
the display. Here the temperature compensation involves the adaptation of the Slope and the
electrode offset to the measured temperature.
P3.3 Reference Temperature
Conductivity measurement strongly depends on temperature.
If the temperature of a sample increases, its viscosity decreases and this leads to an increase in the mobility
of the ions and the measured conductivity, although the concentration remains constant.
For each conductivity measurement, the temperature to which it refers must be specified, otherwise it is a
result without value. Generally, temperature refers to 25 °C or, more rarely, 20 °C.
This device measures conductivity at real temperature (ATC or MTC) and then converts it to the reference
temperature using the correction factor chosen in program P3.4.
Access this setup menu to set the temperature to which you want to refer the Conductivity

measurement.
 The device can report conductivity from 15 to 30°C. By default, it is 25°C which is correct for most of
the analyses.
P3.4 Temperature compensation Factor
It is important to know the temperature dependence (% change in conductivity per °C) of the sample being
measured.
Access this menu to change the temperature compensation factor.

 By default, 1.91%/°C is set which is suitable for most of the analyses.
 Press the key
enter the new coefficient. Confirm with key
Compensation coefficients for special solutions and for groups of substances are shown in the following
table:
Solution
NaCl Saline solution
5% NaOH Solution
Diluted ammonia solution
10% Hydrochloric acid solution
5% Sulfuric acid solution
UM Serie 70Vio EN rev. 1 04.06.2020
, the value flashes and as indicated by the icon
(%/°C)
2.12
1.72
1.88
1.32
0.96
24
, use the directional keys to
.
Solution
1.5% Hydrofluoric acid
Acids
Bases
Salts
Drinking water
EN
(%/°C)
7.20
0.9 - 1.60
1.7 – 2.2
2.2 - 3.0
2.0