4.3
Electrode refresh procedure
The pressurized electrode in the Rosemount
™
Hx338+ has a storage life of one year
without an electrode refresh. At one year of shelf life, all sensors should be refreshed for
peak performance. Please follow this procedure for refreshing the sensor.
Prerequisites
Select the two refresh solutions. A 0.4-4% by weight sodium hydroxide (NaOH) solution for
a base and a 0.73-3.65% by weight hydrochloric acid (HCl) solution for an acid are
recommended. Also, a potassium chloride (KCl) solution is needed for cleaning and
storage.
Record the sensor serial number, lot number, and date of manufacturing on a worksheet.
Remove sensor from the package. Inspect the connection, electrode, and glass for any
defects or scratches and remove the cap by relieving the rubber gasket.
Procedure
1.
Clean the sensor with water; bottled or mineral water is recommended.
2.
Place the sensor electrodes into the NaOH solution for 10 minutes.
3.
Rinse the electrodes with water.
4.
Place the electrodes into the HCl solution for 10 minutes.
5.
Rinse the electrodes with water.
6.
Place the electrodes into the KCl solution for a minimum of 60 minutes.
Zero and calibrate the sensor, following the procedure highlighted in
refresh procedure and replace the cap with fresh KCl solution covering the sensor bulb and
reference junction.
Calibration and maintenance
12
Quick Start Guide