User Guide

Instruction Manual DO 100

4.2 DO Calibration in Air (with ATC) –% Saturation Mode

You can calibrate this meter quickly and easily in air. The exact calibration value depends on

barometric pressure. The meter is set to a factory default of 760 mm Hg, which results in a

calibration value of 100% saturation in air.

NOTE: If the barometric pressure setting has been changed from 760 mm Hg, the calibration

value in air will automatically adjust to a value other than 100%. The adjusted value will be

correct for the new barometric pressure setting. See Section 8.23 for barometric pressure

setting.

To calibrate 100% Saturation:

1. Press MODE key to select % Saturation mode.

2. Rinse the probe well with deionised rinse water. For best

accuracy, wipe the end of the probe dry. Do not touch the

membrane.

3. Hold the probe in the air gently with the sensor facing

down and press CAL key to calibrate the meter. The LCD

will show a “CAL” mode. The primary display will show

the current value of measurement and the secondary

display will show “100.0” to which the meter is going to be

calibrated. Wait for the reading to stabilise.

4. Press ENTER key to confirm the calibration. The meter

automatically calibrates to 100% air saturation and

returns to the measurement mode.

NOTE: To exit from DO Calibration mode without

confirming calibration, DO NOT press ENTER.

Press CAL/MEAS instead.

Figure 8: Calibration for 100%

Saturation