( is a good time to check that the air a...)Fundamentals of Fermentation: Techniques For Benchtop Fermentors

The pH probe must be inspected prior to insertion to ensure that enough electrolyte is present and in good condition. The rubber stoppers must be checked to ensure that they are secure. The pH probe must be properly calibrated prior to insertion in the headplate. (Be sure to carefully follow the manufacturer's instructions for probe calibration which come with the probe and with the fermentor. See also Appendix at the end of this document for calibration information.) It is often necessary to coat the probe with a very thin layer of glycerin or deionized water in order to avoid jamming or breaking it during insertion. The pH probe must be inserted using carefully, using two hands, with one hand holding the base of the probe near the port opening. The insertion must never be forced. Never insert the pH probe until the headplate is properly secured.

(This is also true for the D.O. probe as well.) The D.O. probe must be checked to ensure that the required amount of electrolyte is present prior to insertion, and we usually exchange electrolyte for each new run. The D.O. probe's membrane must also be inspected prior to use. It is absolutely critical that both the pH and D.O. probes have their protective caps on prior to autoclaving, and these should, in fact, be on except when the probe is being hooked up to the unit. NEVER autoclave a pH probe or DO probe without the protective cap in place.

The glass wool for the sampler is prepared by rolling a small quantity up and inserting it into the small tube that attaches to the bulb. It may be necessary to trim any glass wool fibers that stick out. Note that it is possible and undesirable to pack glass wool too tightly. This can be checked for by using the bulb and a sampling tube to see if vacuum can b
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