
13
7.
Select Primary Calibration for Channel 1, 2 or 3.
(e.g.
→
→
F1:Calibrate
F1:Calibrate
→
→
F1:Channel 1
F1:Channel 1
→
→
F1:Primary
F1:Primary
).
The primary calibration screen is now displayed. The current reading is displayed on the top
left, followed by the actual mV data coming from the sensor. The message “
Cal?
Cal?
” instead of
the reading indicates that the
900-I3
is currently not Primary calibrated. For example…
Cal? 0.1
Cal? 0.1 25.0
25.0
O
O
c
c
Ion 100.ppM Calibration, Press Enter
Ion 100.ppM Calibration, Press Enter
When the mV reading has stabilised, press
to calibrate to the Primary Standard value.
Press
to quit without calibrating.
The
900-I3
will now display the Offset of the Ion Selective Electrode, before asking if you
wish to go on to a Secondary Calibration…
Press Enter to go on for Second Standard
Press Enter to go on for Second Standard
Calibration {Slope}, or Menu to Quit
Calibration {Slope}, or Menu to Quit
Note that the “
∗∗
” will not removed from the Specific Ion readout until a Secondary calibration
has been successfully performed
8.
Rinse the Sensors in distilled water and blot dry.
Secondary Calibration
9.
Place the Ion Selective, Reference and Temperature sensors into the Secondary Standard.
Ensure that the Ion Selective Electrode sensing surface and the reference electrode’s reference
junction are both covered, as per the diagram in step 6, above.
Ensure that any Ionic Strength Adjusting Buffer (ISAB) that may be required has been added
(see the Ion Selective Electrode’s handbook).
A magnetic stirrer providing constant, gentle stirring generally improves stability.
10.
Select Secondary Calibration for the same Channel as selected in step 7, above.
(e.g.
→
→
F1:Calibrate
F1:Calibrate
→
→
F1:Channel 1
F1:Channel 1
→
→
F3:Secondary
F3:Secondary
).
The
900-I3
will have done this for you if you pressed
at the end of step 7.
The secondary calibration screen is now displayed. The current reading is displayed on the top
left, followed by the actual mV data coming from the sensor. A “
∗∗
” in place of the decimal
point indicates that the
900-I3
is currently not Secondary calibrated. For example…
11*0ppM 56.7mV 25.0
11*0ppM 56.7mV 25.0
O
O
c
c
Ion 10.0ppM Calibration, Press Enter
Ion 10.0ppM Calibration, Press Enter
When the mV reading has stabilised, press
to calibrate to the Secondary Standard
value.
Press
to quit without calibrating.
The
900-I3
will now display the Slope of the Ion Selective Electrode.
A “
∗∗
” in the display will be replaced by a decimal point after a successful 2-point Slope
calibration, for the Channel that was calibrated.
11.
The
900-I3
is now ready for Specific Ion measurements for the Channel that was calibrated.
Rinse the Ion Selective, Reference and Temperature sensors in distilled water and blot dry
before placing them into unknown samples.