6
Prepare the membrane solution according to the instructions on the
bottle. After mixing, allow the solution to sit for 1 hour. This will help
prevent air bubbles from later developing under the membrane.
Ensure you are using the correct electrolyte solution for the correct
sensor. Galvanic sensors utilize electrolyte with a light blue label
and Polarographic sensors utilize electrolyte with a white label. The
Dissolved Oxygen sensor is supplied with cap membranes specific
to the sensor type ordered (Polarographic or Galvanic). 5913 and
5914 membrane kits are for Galvanic sensors and the 5908 and 5909
membrane kits are for Polarographic sensors.
Remove and discard or save the red protective cap. Thoroughly rinse
the sensor tip with distilled or deionized water. Fill the cap membrane
3⁄4 full of electrolyte solution, then tap the cap with a finger to release
any trapped air. Be careful not to touch the membrane portion of the
cap. Thread the membrane cap onto the sensor, moderately tight.
Do not use a tool. It’s typical for some of the electrolyte solution to
spill over. It is best to allow the new cap to remain on a new sensor
overnight before trying to calibrate. For detailed instructions on
changing a membrane cap, see the Care, Maintenance, and Storage
section of this manual.
RUN SCREEN
Press the power/backlight key
to turn the instrument on. The
instrument will run through a self test and briefly display a splash screen
with system information before displaying the main Run screen (figure
5). The first time the Pro20/Pro20i is turned on, it will step through
language, sensor, and membrane selections; see the First Power On
section of this manual for more information.
Figure 5, Run screen.
