Cal 2-p l h 1.00 – Thermo Fisher Scientific Alpha DO 1000 User Manual

Page 20

CALIBRATION MODE

You can reach the Calibration mode directly from the
Measurement mode by pressing the CAL key and
entering the Calibration security code. You can also
reach the Calibration mode from the Advanced Setup
mode.

6.1 Dissolved

Oxygen

Calibration

If the units of measure is in mg/l (default), then the
calibration is also carried out in mg/l. The Dissolved
Oxygen Controller allows a one- or two-point calibration.

1. Enter Calibration mode. While in the

Measurement mode, push the CAL key and
scroll to Calibration code “11”. Push the
ENTER key again. The upper and lower display
reads “CAL dO”.

2. Press the ENTER key. Use the

▲ or ▼ keys to

select 1- or 2-calibration points.

3. For One-Point Calibration, only Hi-value

calibration is possible. The probe is allowed to
equilibrate in a solution containing 8.24 mg/l of
dissolved oxygen. The “CAL” indicator flashes
at the top, right-hand corner. When reading is
stable, the “READY” annunciator comes on.
Use the

▲ or ▼ keys to adjust the displayed

value to the correct value. Press ENTER key to
accept the value and the controller displays the
status of the probe.

4. For Two-Point Calibration, calibration is

carried out at the Lo-value first, usually zero
oxygen solution. Immerse the probe in the
solution (low levels of dissolved oxygen) and
allow it to stabilise. When the reading is stable,
the “READY” annunciator comes on. Use the

▲

▼ keys to adjust the displayed value to the

correct value. Press the ENTER key to accept
the value.

NOTE: If the displayed value is > ±0.4 mg/l, the controller will not

accept the zero calibration and retains the previous calibration
values.

HOLD

READY

mg/l

SETUP

CAL

Cal

2-p

1.00

CAL

0.00

8.24

24.2