20
7. Conductivity Calibration
Before attempting a Conductivity calibration ensure that Temperature has been correctly calibrated
(see section 6). A “
∗∗
” in the Temperature readout in place of the decimal point indicates that
Temperature is NOT calibrated.
See section 18 for details on how to select the Conductivity readout units that you wish to use.
7.1 Conductivity Calibration Procedure
1. Ensure that the
hydro
CHEM
is in Standby mode (see section 3.3).
2. Plug the Conductivity sensor into the
Cond/Temp
socket.
3. Rinse the sensor in distilled water. Shake off as much water as possible. Blot the outside of the
sensor dry.
Zero Calibration
4. Let the sensor dry in air.
5. Select Conductivity Calibration (
→
→
F1:Calibrate
→
→
F1:Conductivity
).
6. The
hydro
CHEM
will recognise the low Conductivity signal and attempt a Zero calibration.
For example…
0*1mS/cm 25.0
O
c
Press Enter to Calibrate to Zero
7. When the reading has stabilised at or near zero, press
to calibrate or
to quit. The"
∗
"
will not be removed after a zero calibration.
Standard Calibration
8. Place the Conductivity sensor into a sample of 2.76 S/cm or 1.41 S/cm standard so that it is
immersed at least to the first vent hole, as per the diagram below.
DO NOT
place the sensor directly into the bottle of standard. Discard the used sample of
standard after use.
9. Select Conductivity Calibration (
→
→
F1:Calibrate
→
→
F1:Conductivity
). The
calibration screen will be displayed, with the Conductivity standard to be used. For example…
2*5mS/cm 25.0
O
c
Press Enter to Calibrate to 2.76mS/cm
10. When the reading has stabilised, press
to calibrate. The"
∗
"will now be replaced by a
decimal point if calibration was successful.
11. The
hydro
CHEM
is now calibrated for Conductivity and is ready for use in this mode.
