INSTRUMENT OPERATION
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59
Chapter 6
Figure 12.
Ag/AgCl pellet assembly.
Use
Insertion of Pipette
Make sure the electrode cap is loosened so that pressure on the cone washer is
relieved, but do not remove the pipette cap. Push the back end of the pipette
through the pipette cap and cone washer until it presses against the pipette seat.
Gently tighten the pipette cap so that the pipette is gripped firmly.
To minimize cutting of the cone washer by the sharp back end of the pipette, you
can smooth the pipette edges by rotating the back end of the pipette in a bunsen
burner flame before filling the pipette with salt solution.
Cleaning
For lowest noise, keep the holder clean. Frequently rinse the holder with distilled
water. If more thorough cleaning is required, briefly wash in ethanol or mild soapy
water. Never use methanol or strong solvents.
Filling Pipette
Only the taper and a few millimeters of the shaft of the pipette should be filled with
solution. The chlorided tip of the wire should be inserted into this solution. Avoid
wetting the holder since this will increase the noise.