We have but that was 4 years ago when we built the place. I don't remember much of the results except that the three labs didn't agree on much of anything. They were ag water testing labs, not testing for human consumption. We've been tempted to put our purified water in a test vial and send it to the company that does our drinking well water testing (mandated that we do it every quarter) BUT if they flub up and report our irrigation water test results, assuming it failed something, as our drinking water then we're put on a monthly test schedule for a year. We're not super impressed with the organizational skills so we aren't likely to make it a routine thing. If we do ever do it I'll show up out of company uniform, pay cash, and tell them it's my personal well at home.
Gotcha, and totally understand not wanting to do something that may turn into a needless headache. I've been looking for a rural property, so water quality and testing has been on my radar. I fully plan to make offers on property continent on well water quality results.
Nice! Did you roll your own charts? It looks like amichart to me but I could be wrong. How'd you go about getting liquid pressure? The transducer we use on the VFD pump controllers is a f*cking expensive bugger at about $400 a pop. For some darned reason we burned through a few in the early years and I really hated knowing we bought them like disposables. I'd also like an inexpensive way of getting PSI readings on various lines electronically.
They are actually jQuery UI charts. Works well, fairly easy to customize, and looks good.
For pressure, I used these: [eBay link] http://tinyurl.com/j3aq57h
Note, these come in various different pressure ranges. For best accuracy, choose your upper bound as low as possible.
They are analog output, so I had to walk the signal through an ADC [MCP3008], but they work okay. In my application, I should have used a 12 bit ADC. I do question the sensors linearity. Coincidentally, I'm working on a deadweight pressure tester right now, so perhaps I'll test these buggers against a known standard. As with most things in measurement, it's probably of how much precision you want to pay for.
The temperature sensors are DS18B20 units. Highly recommended. Couple bucks a pop, already calibrated, and SPI interface which lets any number of them talk to the Pi on a single pin. Only external part required is a pull up resistor.
