Week 2 Day 2

Today is really going to happen in two chunks. This morning we started out working with the pH circuit. We actually built the circuit, loaded the code and did some tests. After that Lori and Joe did similar tests with the Spark probes to compare. In the afternoon we will be listening to a presentation from the NI representative about LabView.

The first thing we started on was having Joe and Lori do some sample tests with the Spark probes while I researched temperature probes. They measured Coke, warm and cold coffee, unsweetened tea and distilled water.

Once they had a handle on that process Dr. Fu and his graduate student came in to show us a model of the circuit we will be building for the pH sensor.

After walking us through the circuit and the code he left us to make our own version modeled on what he showed us. The process started with Yixin doing some quick soldering for us to get the adapter mounted to the probe hook-up. 

After that I built a circuit to mimic the one Dr. Fu put together.

It ended up looking pretty good. (Mines on the bottom of the image!)

Once we had it built we loaded the code and started taking measurements.

We got it calibrated and only had a drift of 0.5 on the pH 4 standard and 0.12 on the pH 10 standard. The pH 7 standard came in spot on. Not bad!

Once we had some date from our pH probe we took readings with the Spark for comparisons sake and ours was actually slightly more accurate (in this admittedly limited test).

All in all that was a pretty successful morning. The afternoon was a three hour seminar designed to introduce us to National Instruments LabView and MyDAQ. It was more sales pitch than seminar, really, but I have to admit they have some pretty interesting products that I wouldn't mind having for some hands on instruction with my kids. We will see... here is what a MyDAQ looks like.

This thing replaces a huge stack of testing equipment that engineering students typically use. It was originally intended to be sold to individual college students in the book store the same way you'd buy a calculator. NI was surprised that most Universities just bought a set and loaned them out to students. So, in order to generate better cash flow NI has started marketing it to high schools and middle schools. They have some mini modules that  you can add on that are really neat. You should check it out if you teach sciences.