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5.7 Resistivity Calibration
Before attempting a Resistivity calibration, ensure that the
smart
CHEM
-C
has been set up
correctly according to sections 5.1 to 5.6. The calibration procedure detailed below uses the sample
configurations shown in sections 5.1 to 5.6.
Automatic Temperature Compensation can be done via a temperature sensor inside the Resistivity
sensor, or via the separate stainless steel temperature probe. Using the Resistivity sensor for ATC is
more convenient, but the separate temperature probe has a faster response. If the separate
temperature probe is plugged in, the
smart
CHEM
-C
always uses this for temperature readout and
ATC. To use the Resistivity sensor for Temperature readout and ATC, the separate temperature
sensor must be disconnected. Please choose one or the other according to your preference.
Ensure that Temperature has been correctly calibrated (see section 7.1). A “
∗∗
” in the Temperature
readout in place of the decimal point indicates that Temperature is NOT calibrated.
1. Plug the Resistivity sensor into the
Cond / TDS
socket. If required, plug the separate
Temperature sensor into the
Temperature
socket.
2. Rinse the sensor(s) in distilled water. Shake off as much water as possible. Blot the outside of
the sensor(s) dry. DO NOT BLOT THE RESISTIVITY ELECTRODE PLATES.
Air Calibration
3. Let the sensor dry in air.
4. Select Resistivity Calibration (
→
→
F1:Calibrate
→
→
F1:Resistivity
).
5. The
smart
CHEM
-C
will recognise the over-range Resistivity signal and attempt an Air
calibration. For example…
Resist. OverRK
Ω
Ω
.cm
ZERO
Calibration
Press Enter
6. Press
to calibrate. The Automatic Stability Function will now show a and highlight the
reading while it is unstable…
Resist.
OverR
K
Ω
Ω
.cm
ZERO
Calibration
Waiting to Stabilise
When the Resistivity reading has stabilised, the unit will calibrate itself.
To calibrate immediately without waiting for complete stability, press
to disable the
Automatic Stability Function.
The “
∗
” will not be removed after an Air calibration.
Continued over the page…