The shaft of the Go Direct® Ethanol Vapor, order code GDX-ETOH, $149 is slightly smaller than the Ethanol Sensor, order code ETH-BTA, $119. This means that the stopper #6 Stopper for Ethanol Sensor, order code ETH-STOP, $4 will not hold the Go Direct Ethanol Vapor in place.
To fix this problem, simply trim the stopper with a razor blade and make the split in the stopper a little wider. Start by taking cutting less than 1 mm off the stopper. This should fix the problem.
Please note that we always recommend using a utility clamp or a Electrode Support, order code ESUP, $10 to secure any of our ethanol sensors during use. The stopper is designed to act as a seal, and should not be used to secure any sensor above a solution.