Hach EZ Series Basic User Manual page 32

9.13 Replace the tubing
Replace all of the analyzer tubing: pinch valve tubing, sample tubing, reagents tubing, drain and rinse
tubing. Tubing sets are available based on the analyzer model.
1. Replace the tubing and make the connections at the same fittings.
2. When the procedure is complete, start the analyzer and look for leaks.
9.14 Replace the electrodes
The usual lifespan of an electrode is approximately one year with standard laboratory use, but the
actual lifespan of the sensing module can change based on the type of samples. Replace the
electrode when the slope decreases and readings start to drift. Before an electrode is replaced, make
sure that the unusual measurements are caused by a defective sensing module.
Refer to the documentation supplied with the electrode for additional information.
9.15 Calibrate the photometer with bi-distilled water
1. Fill the analysis vessel with demineralized water.
2. Set the voltage of the sensor output to 9.5 V.
3. Do a calibration.
The absorbance output value is ~0 mAU.
4. Drain the analysis vessel.
The absorbance output value is approximately 300 mAU.
5. If no difference is seen between the two absorbance output values, the photometer is not
operating correctly.
9.16 Replace the micropump duckbills
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