Yesterday, I spent the bulk of the day working on a pH measurement system, and working on material for the instrumentation and process control clas.
The measurement system is strange. With a voltmeter, I can read around 200 mV difference between a pH of 4.0 and 10.0. With any piece of National Instruments equipment, it shows us as less than 20 mV change, and noisy enough that the data is only semi-useful. I’ve usd a USB-6008, a MyDAq, and an SCXI-1200. I built a little amplifier with a 741 op amp, but haven’t tested it, as I don’t know what the NI hardware is doing to make the voltage difference drop so much.
Otherwise, yesterday was an uneventful day. I chatted with an old friend on the bus for several hours, and it was nice to catch up.
Thank you for reading my post.