You might consider looking for a ph transmitter on ebay that has all the necessary circuitry and outputs a voltage or current signal. How are you doing your application? What language, and have you had to custom write the whole thing? Our next step is to load the application on the touch screen panel pc mounted in the panel door and connect it to the site wireless network. Future software enhancements include making the integrated panel PC a server for a custom Java applet that shows the status of the hardware. Web served to any PC with internet connection. Additionaly, we are considering the addition of a networked security camera to observe the system remotely.