YSI 95 - Manual (Page 8)

YSI Incorporated Model 95 4
SECTION 3 SECTION 3 SECTION 3 SECTION 3 PREPARING THE PROBE PREPARING THE PROBE PREPARING THE PROBE PREPARING THE PROBE
The YSI Model 95 dissolved oxygen probe is shipped wet with a shipping membrane installed. This
protective membrane cap on the probe tip must be removed and replaced with a new membrane cap
filled with MEA probe solution before using the probe. Follow the instructions below to install the
new membrane cap.
3.1 3.1 3.1 3.1 CHOOSING THE CORRECT MEMBRANE CAP CHOOSING THE CORRECT MEMBRANE CAP CHOOSING THE CORRECT MEMBRANE CAP CHOOSING THE CORRECT MEMBRANE CAP
Two different membrane caps are available for the Model 95. The YSI Model 9501 Membrane Cap
Kit is supplied with the Model 95. This kit contains six 0.5 mil (.0005") membrane caps and a bottle
of MEA probe solution (KCl).
NOTE: YSI 9501 Membrane Caps offer the fastest response to changes in DO and are
recommended by YSI for most applications.
For conditions with low flow or stagnant water, a 1 mil (.001") membrane is available (YSI Model
9502 Membrane Cap Kit). This membrane requires less stirring than the 9501, but has a much
slower response. Use this membrane when minimal stirring (<2"/sec) is available.
3.2 3.2 3.2 3.2 MEMBRANE CAP INSTALLATION MEMBRANE CAP INSTALLATION MEMBRANE CAP INSTALLATION MEMBRANE CAP INSTALLATION
WARNING: Use only YSI MEA probe solution in the membrane cap. Any other solution will
damage the MEA sensor.
To install a new membrane cap on your YSI Model 95 dissolved oxygen probe:
1. Unscrew and remove the probe sensor guard (see Figure 2 ).
2. Unscrew and remove the old membrane cap.
3. Thoroughly rinse the sensor tip with distilled water.
4. Hold the membrane cap and add 8 to 9 drops of MEA probe solution (about half full).
5. Tap the bottom of the cap with your finger a few times to remove any trapped air bubbles.
CAUTION: Do not touch the membrane surface.
6. Screw the membrane cap onto the probe tightly by hand (to prevent leakage of electrolyte). A
small amount of probe solution should overflow.
7. Shake off any excess probe solution and rinse the stainless steel thoroughly with distilled water
to prevent corrosion.