Campbell Scientific CS526 ISFET pH Probe - Manual (Page 19)

CS526 ISFET pH Probe
Clean the probe if any of the following occur:
• Low slope
• Drift
• Instability of the reading
• Slow calibration
• Probe will not calibrate
• pH value doesn’t change as expected when changing samples
Additionally, when sampling colored liquids, the probe should be cleaned
when the reference diaphragm is no longer white.
9.1.2 Cleaning Procedure
Read Section 9.1.2.1, Cleaning Tips, before following this procedure.
1. Place probe in warm tap water (~60°) with a mild detergent and soak for 5
minutes, stir periodically.
2. Scrub the surface of the chip and the diaphragm (FIGURE 9-1) with a soft
toothbrush and water with a mild detergent (see Caution).
Never brush the probe tip, especially the ISFET chip, before
rinsing and flushing thoroughly with water. Before rinsing
debris and particles may be on the sensor surface and
brushing them into the sensor may damage it. When in
doubt, soak the probe for a while in warm water with a mild
detergent.
FIGURE 9-1. Tip of the CS526 probe
3. Rinse thoroughly with deionized water.
4. Revitalize the probe (Section 9.1.3, Revitalizing)
5. Calibrate the probe (Appendix C, Calibration).
CAUTION
Diaphragm
Chip
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