Thermo Fisher Scientific CyberScan DO 300 - Manual (Page 14)

Instruction Manual DO 300
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5 MEASUREMENT
5.1 Taking DO readings
During measurement, the probe can be:
z Fully immersed in the solution
z Partially immersed in the solution
Do not allow the probe’s membrane surface to touch anything!
It is always advisable to insert the probe guard (refer to Figure
34 and 35 on pages 38 and 39)
IMPORTANT: Since the DO probe consumes oxygen from the
sample, the sample must constantly flow past the membrane
to achieve more accurate readings. You can use a stirrer to
accomplish this.
To take measurements:
1. Rinse the probe well with DI rinse water or rinse solution.
2. Select the appropriate measurement mode. Press the
MODE key to toggle between modes:
z % Saturation
z mg/L (or ppm)
z date/time clock
3. Dip the probe into the sample. Stir the solution gently
using the probe to homogenise the sample. Make sure
that the sample is continuously flowing past the
membrane sensor.
4. Note the reading on the display. If the READY
indicator is switched on, it will appear when the reading
is stable.
5. You can press the (LIGHT) key to activate the backlit
LCD. This helps you read measurements in dimly lit areas.
Figure 9: Change
measurement mode
Figure 10: Taking
measurement