Hach-Lange H-Series Meters Basic User Manual - Manual (Page 17)

Clean the ISFET probe
N O T I C E
Do not use sharp metal objects (a needle, a pin, etc.) to clean the sensor. This can scratch the sensor and cause
permanent damage to the probe.
For use in dairy, cheese or meat applications, soak the probe in Pepsin Cleaning Solution for
15 minutes before the probe is cleaned.
Regularly clean a non-glass probe:
1. Remove the rubber dust cap from the probe, then rinse with new deionized water.
2. Use a soft-bristle toothbrush and a mild detergent (a few drops of dish soap in a warm cup of
water) to carefully clean the probe.
3. Rinse with new deionized water to remove all debris from the sensor surface.
4. Dry the probe with a lint-free cloth.
5. Calibrate the probe again. Refer to
Calibrate the ISFET probe on page 16, then Prepare the
probe for storage on page 16.
Repair the ISFET probes
N O T I C E
Do not use the probe to find out if the buffer is above 60 °C (140 °F). If the probe is suddenly put into very hot
liquid, the probe can be permanently damaged.
Monitor how long the probes are in dry storage. If the probes are in storage for an extended period of
time, the KCI gel at the reference junction can crystallize.
1. Heat pH 7 buffer to approximately 45 to 60 °C (115 to 140 °F).
2. Soak the probe for 2 minutes.
3. Put the probe in room temperature pH 7.00 buffer and let cool.
BNC electrode maintenance
Prevent unstable readings:
• Keep the probe in an electrode storage solution.
• Start measurements with at least a 2-point calibration. Update often with 1, 2 or 3-point
calibrations.
• Use new buffers and new deionized rinse solution.
• Use buffer solutions with pH values no larger than 3 pH units apart. Ideally, the buffers bracket the
anticipated pH values of the unmeasured samples.
• Use deionized water to rinse residual buffer and sample solutions from the probe after calibration
and measurement.
• Calibrate at the same temperature as the sample solution. Although the meter has an ATC, get the
best results when the calibration buffers and the sample are the same temperature.
• Keep the connectors clean and dry. Dirty or damp connectors can cause unstable readings.
Troubleshooting
Problem Possible cause Solution
No display Automatic shutdown set the
power to off. Set the power to on again.
There is no power. Replace the batteries.
English 17