Calibrating With A Known Nacl Standard - Hach Sension 156 Manual

SECTION 4,
continued

4.3.1 Calibrating with a Known NaCl Standard

2. Enter/adjust the cell constant of the conductivity probe. See
Section 4.3.3 for instructions on this calibration method.
Hach's Conductivity probe is shipped with a 1000 µS/cm
(at 25 °C) NaCl standard solution. For typical applications with
conductivity of 0–10,000 µS (10 mS/cm), calibrate with this
standard to achieve the accuracy specified for the meter. Outside
this range, calibrate using a standard that lies closer to the
measurement range. In general, using a calibration standard that
is closer to your measurement range results in greater accuracy.
Hach offers several conductivity standards.
1. Make sure the meter is in Conductivity Reading mode.
2. Place the probe in a conductivity standard that is in the
expected range of the samples. Agitate the probe to dislodge
bubbles in the cell. Avoid resting the probe on the bottom or
side of the container.
3. Press . Icons that represent the active navigation keys will
CAL
appear in the lower part of the display.
The meter will recall the most recent type of calibration. Look at
the units field to see what kind of calibration is active. The units
will be one of the following forms:
Units
µS/cm
mS/cm
1/cm
4. Scroll to the preferred units using the
5. Use the number keys to change the numeric value, if desired.
The value entered must be the standard's conductivity value
at a reference temperature of 25 °C.
Note: All Hach standards have the conductivity value corresponding
to the 25 °C reference temperature printed on their labels.
It is not necessary to fill up the numeric entry screen before
moving on. To clear the numeric display, press
40
Calibration Method
Known standard expressed in µS/cm
Known standard expressed in mS/cm
Enter/adjust cell constant (see Section 4.3.3)
or
UP DOWN ARROWS
.
CE
.