Electro-Chemical Devices (ECD) L20 - Manual (Page 11)

then press “Slope” key to calibrate. Once the unit
calibrates the second point, the “SLOPE” icon will flash.
The unit is ready to be sloped at the third buffer.
[Note: At this moment, press the “Mode” key, to exit the
calibration mode. Dual point calibration is complete.]
5. Rinse the pH probe in distilled water and immerse it in the
third buffer solution (either 9.18/10.01 or 4.00/4.01), then
press “Slope” key to calibrate. Once the unit calibrates the
third point and the unit will automatically exit the
calibration mode. The three point calibration is complete.
6. The unit calculates and compensates for the pH electrode
slope deviation corresponding to the values of the three
calibration buffers. After calibration, press and hold
“Mea./Eff.” key for about 5 seconds to display the new
electrode efficiency.
[Note: For accurate measurements, it is recommended
that pH calibration is preformed once a week and after
replacing the electrode.]
C. pH Measurements
To take pH measurements, the pre-selected buffer solution set must
lit up, indicating the unit is Single point or dual-point or three-point
calibrated and ready for measurements. If buffer solution set
flashes, perform a pH calibration before taking measurements.
Measurement with an ATC/Temp probe in the pH
AUTOLOCK mode
1. Connect the pH electrode to the BNC connector and the
ATC/Temp probe to the ATC/Temp connector of the unit.
The “ATC” icon will light up.
2. Press “Mode” key until “pH” icon and “AUTO” icon light
up.
3. Rinse the pH electrode and ATC/temp probe with distilled
water and immerse in the sample to be measured.
Remove any air bubbles trapped around the probe by
shaking or stirring the probe.
4. Press the “Mea.” key. The “WAIT” icon will start flashing.
The unit is waiting for a stable reading. The display will
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