24 sal – Thermo Fisher Scientific Alpha DO 1000 User Manual

Page 23

7 ADVANCED

SET-UP

MODE

7.1

Electrode Offest (OFS), Salinity and Pressure sub-function

This mode allows you to change the offset parameter to make reading corrections
without removing the electrode from the control system. You can make adjustments
of up to ±2.00ppm; ±2.00 mg/l; or ±10.0%. At the end of the offset adjustment, the
salinity value, followed by the pressure values (in mmHg or Pascal) respectively, is
entered.

HOLD

SETUP

mg/l

ppt

ofs

0.02

760

0.0

8.24

sal

1. In this mode, the controller will add or subtract the value from the

measured dissolved oxygen value and display the correct value. However,
if you need to offset the value beyond the average offset you would expect
in your application type, consider a full calibration or even electrode
replacement.

2. Take a sample from the system. Record the controller’s Dissolved Oxygen

reading at the time the sample was taken.

3. Measure the Dissolved Oxygen of your sample using a calibrated

Dissolved Oxygen hand-held meter or bench meter (For a list of Thermo
Scientific Instruments’ DO hand-held meter, refer to section on
Accessories).

4. Record the correct Dissolved Oxygen value.

5. Enter Advanced set-up mode. Push the ENTER key and scroll to

Advanced Set-up security code “22”. Push the ENTER key again.

6. Press

the

▲ or ▼ keys to scroll until the upper display shows “OFS”.

7. Press the ENTER key. The SETUP annunciator appears at the top of the

display. The lower display shows the current measured Dissolved Oxygen
with its respective units. The upper display shows the current offset value.