Cleaning The Instrument; Cleaning The Measuring Block - Hach 9186 Instrument Manual

Maintenance

7.2.2 Cleaning the Instrument

7.2.3 Cleaning the Measuring Block

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8. Reconnect power to the instrument.
With the enclosure securely latched, use a soft cloth and a mild detergent to wipe
the outside of the enclosure. Do not use solvents. Do not allow moisture to enter
the enclosure.
Once a month, check the platinum anode for deposits. If dirty, do not remove, but
clean the measuring block.
1. Turn off the sample flow from the flow meter.
2. Using a syringe, inject 10% nitric acid (Cat. No. 2540-49) into the measuring
cell via the venturi-valve inlet tubing.
3. Wait five minutes for the acid to react.
4. Turn the sample flow on and set 12 L/hour.
5. Recalibrate the instrument. Refer to section 6.4 on page 34.