Quick Start Guide
Orion 720Aplus pH/ISE Meter
Calibration of Ion-Selective Electrodes (ISE) with
Two Standards
1.
Verify selected input is currently in use. If input 1 to be used, the prompt line
should indicate “1-”. If input not correct, press
2nd
, then
channel
repeatedly
until selected input is displayed.
2.
Select concentration mode by pressing
mode
until “CON” is displayed on
main display.
3.
Place electrode(s) into first standard and stir moderately.
4.
Press
calibrate
. The date and time of the last calibration is displayed.
5.
Press
2
then
yes
to select 2 standard calibration.
6.
When “READY ENTER VALUE” is displayed on prompt line, indicating
electrode is stable, enter value of standard and press
yes
. The standard value
is entered, stored and the meter display freezes for three seconds. The meter
automatically switches to standard 2.
7.
Remove electrode(s) from first standard. Rinse with deionized water.
8.
Place electrode(s) into second standard.
9.
When “READY ENTER VALUE” is displayed on the prompt line, indicating
electrode is stable, enter value of standard and press
yes
.
10. The electrode slope is calculated and then actual value is displayed for five
seconds. Meter will then automatically proceeds to the MEASURE mode.
11. Remove electrode(s) from standard. Rinse with deionized water. Place
electrode(s) into sample. When “RDY” is displayed record sample results.
See the appropriate electrode instruction manual for preparation of sensing and
reference electrodes, required solutions (ionic strength adjusters, standards, etc.)
and other special requirements. For best results during calibration, always use the
most dilute standard first, and always use a fresh aliquot of standard.
pH Autocalibration with Two Buffers
1.
Verify selected input is currently in use. If input 1 to be used, prompt line
should indicate “1-”. If input not correct, press
2nd
, then
channel
repeatedly
until selected channel is displayed.
2.
Select pH mode by pressing
mode
until “pH” displayed on main display.
3.
Place electrode(s) into pH 7 buffer and stir moderately.
4.
Press
calibrate
. The date and time of the last calibration is displayed.
5.
Press
2
then
yes
to select two buffer calibration.
6.
When “RDY” is displayed on prompt line, indicating electrode stability, press
yes
. The buffer value is entered, stored and meter display freezes for three
seconds. The meter automatically switches to buffer 2.
7.
Remove electrode(s) from first buffer. Rinse with deionized water.
8.
Place electrode(s) into second buffer.
9.
When “RDY” is displayed on prompt line, press
yes
.
10. The electrode slope is calculated and then actual value (in percent) is
displayed for five seconds. Meter will then automatically proceed to the
MEASURE mode.
11. Remove electrode(s) from buffer. Rinse with deionized water. Place
electrode(s) into sample. When “RDY” is displayed record the sample results.
233944-001 Rev. C
