User Guide

Instruction Manual DO 100
9
4.1 Temperature Calibration
DO in mg/L is dependent on temperature, so it is first necessary to
calibrate or verify the temperature reading. Temperature calibration is
accessible from the mg/L or ppm measurement mode. This is
illustrated in the flow diagram in Figure 7.
The temperature sensor is part of the DO probe and the “ATC”
annunciator will light up on the LCD screen once the probe is
connected correctly to the meter.
1. Dip the DO probe into a solution with known temperature. Allow
sufficient time for the temperature to stabilise.
NOTE: Use an accurate temperature meter or bath to determine
the solution’s temperature.
2. Ensure that the meter is in measurement mode. Press MODE
key if necessary to select mg/L mode.
3. Press CAL key to go into calibration mode of mg/L. The primary
display shows the measured DO in mg/L and the secondary
display shows the temperature.
4. Press MODE key to go into temperature offset adjustment mode.
The primary and secondary displays will show the temperature
values. See Figure 6.
5. Press MI/ or MR/ key to set the correct temperature value.
NOTE: The meter allows a limit of ± 10 °C variation between the
original and the adjusted value.
6. Press ENTER key to confirm the adjusted temperature. The
temperature probe is now calibrated.
NOTE: To exit from Temperature Calibration mode without
confirming calibration, press CAL/MEAS key.
NOTE: Since temperature readings affect the accuracy of the
mg/L measurements, it is strongly recommended to
carry out a mg/L calibration after a temperature
calibration is done.
Figure 6: Temperature
Calibration