Excellent Kirk! Both you and Chris have given me some ideas. Somewhere in the basement I have a roll of Teflon tubing, maybe I can butt splice it like you did, Kirk. Hmm.
Here are a few pictures of my set up.
This is an overall view. The controls box is on the right. It has the power supply and controls for the mixer and the temp controller for the crock pot. I've left space in it to add other things if I decide to do that. I am thinking about adding a temp unit and a meter of some kind for vAg.
Here's a closer picture set up for measuring vAg. This is roughly copied from a diagram in an old thesis from RIT.
Top to bottom, the EXPO marker is the reference electrode stuck into a funnel filled with KNO3 solution. This sits on top of the salt bridge that is made from a vinyl tube connected to a pen body. The end of the pen body is plugged with a thick felt and partially filled with KNO3 solution mixed with agar. The other tube with the red lead attached is the Silver Bromide ISE. The leads go to an Extech multimeter. vAg measurement with this gear seems to work very well. The blue container at the back of the pot is for storing the kettle end of the salt bridge. The top end is covered with saran wrap when not in use. Electrodes have their own storage containers.
At left is the temp probe going to the PID temperature controller for the pot. The mixer is at right. It is a hardware store paint mixer connected to a 500 rpm geared motor. The mixer controller in the control box allows me to control the mixer speed from about 50 rpm to about 1500 rpm in 10 steps.
The red object at the bottom of the pot is a plastic lid to keep the kettle from being in contact with the pot bottom which sometimes gets pretty hot.
There is also a kitchen type thermometer like Kirk shows to monitor the kettle temperature. When connected, the syringe pump sits to the left on a brick. The tubes are clipped to the side of the kettle and enter the solution right next to the mixer.
-- Jason