13
No
Enable Auto Cals Yes
No
MANUAL CAL SEQUENCE
Ion Std 1
or
Ion Std 2
or
Initiate Cal
Yes
No
Yes
Calibrating Std 1
Electrode mV
–
•
– –
Enter
Cal
Cal
Enter
Cal
Enter
Cal
Enter
– –
•
– –
– –
•
–
or
or
Cal
6
PROGRAMMING…
6.2.2
Operating Page 2
To gain access to the Calibration Page (Operating Page 2), operate the
Cal
switch.
Enable Automatic Calibrations
Select 'Yes' to enable or 'No' to disable the automatic calibrations.
Store.
Advance to next parameter.
Page header.
Advance to next parameter.
Ion Standard 1
Set the value of the 'Low' standard solution (Std 1).
Low value ammonia standard solutions should be avoided. For example, at
ambient temperatures of about 25
°
C, and under normal light conditions, a
0.5 mg
-1
NH
3
solution is expected to lose at least 10% of its concentration over a
seven day period. Because of the instability of such solutions, it is not possible to
programme a standard solution of lower concentration than 0.2 mg l
–1
NH
3
on this
monitor. Solutions as low as 0.2 mg l
–1
can be prepared with care, but must be
used immediately, making it an unsuitable concentration for long term use with the
monitor.
Store.
Advance to next parameter.
Ion Standard 2
Set the value of the 'High' standard solution (Std 2). The concentrations of the two
standard solutions must differ from each other by a factor of at least four.
Store.
Advance to next parameter.
Initiate Calibration (manual)
Select 'Yes' to carry out a manual calibration or 'No' to return to the top of the page.
Enter must be pressed to initiate a manual calibration.
Calibrating Standard 1
The upper display shows the ammonia concentration value. The display remains
until a stable output is obtained from the probe.
Toggle between the two displays.
Electrode Millivolts
Note.
Pressing
Cal
during a calibration aborts the sequence and returns to
normal operation.
When a stable probe output is detected the display automatically advances to the
next parameter.
Continued on next page.
