This is early development stage of an open source automatic alkalinity tester.
System:
- Raspberry pi. Development in Python. Utilizing influxdb and grafana for visual dev.
- Stepper motor for sample fill and reagent dosing
- Dc motor for sample drain
- pH probe and altas pH sensor. Future: reef-pi pH sensor board.
- HCL titrant.
Photo's of the test set up:
The steppers and dosing pumps are Kamoer. Still deciding if I like these steppers.
pH sensor top-right. Raspberry pi 3 shown. Currently using pi-zero w
Stepper motor drivers and ULN2003 for dc motors
Stepper drivers are TMC2100. Started with DRV8255 drivers but way to noisy.
Bluelab double junction pH probe in the picture. Has since changed to atlas's pH probe. The Bluelab was ridiculously slow in between readings
Magnetic stirrer. PC fan with blades removed and a couple small magnets glued on.
Running on the test bench.
Some of the current measurements for testing purposes.
Currently calculating alkalinity by:
- End-point
- inflection point
- modified gran plot method. Via open-source program named Calkulate
Long term precision is probably around 0.25 - .35 dkH alkalinity. Still a bit of work to do
Chris
System:
- Raspberry pi. Development in Python. Utilizing influxdb and grafana for visual dev.
- Stepper motor for sample fill and reagent dosing
- Dc motor for sample drain
- pH probe and altas pH sensor. Future: reef-pi pH sensor board.
- HCL titrant.
Photo's of the test set up:
The steppers and dosing pumps are Kamoer. Still deciding if I like these steppers.
pH sensor top-right. Raspberry pi 3 shown. Currently using pi-zero w
Stepper motor drivers and ULN2003 for dc motors
Stepper drivers are TMC2100. Started with DRV8255 drivers but way to noisy.
Bluelab double junction pH probe in the picture. Has since changed to atlas's pH probe. The Bluelab was ridiculously slow in between readings
Magnetic stirrer. PC fan with blades removed and a couple small magnets glued on.
Running on the test bench.
Some of the current measurements for testing purposes.
Currently calculating alkalinity by:
- End-point
- inflection point
- modified gran plot method. Via open-source program named Calkulate
Long term precision is probably around 0.25 - .35 dkH alkalinity. Still a bit of work to do
Chris