dwblair/riffle-conductivity

DIY conductivity sensor designs

Background

Road Salt and the LovoTech network.

• Mark Green and Road Salt
• LoVoTECS

• http://des.nh.gov/organization/divisions/water/wmb/was/salt-reduction-initiative/impacts.htm
• http://www.boston.com/news/local-news/2015/01/16/road-salt-where-does-it-come-from-where-does-it-go
• http://news.nationalgeographic.com/news/2014/02/140212-road-salt-shortages-melting-ice-snow-science/
• http://www.wired.com/2015/03/road-salt-polluting-rivers/
• http://science.howstuffworks.com/nature/climate-weather/atmospheric/road-salt.htm

Salt water intrustion.

https://en.wikipedia.org/wiki/Saltwater_intrusion Groundwater extraction Sea level rise

Agriculture.

http://www.fao.org/docrep/t0667e/t0667e05.htm

Hydraulic Fracturing and pollution.

Fracking http://www.fondriest.com/news/tracking-fracking.htm

Characteristics of a good conductivity sensor

Input signal.

• AC measurement
• AC frequency
• Symmetric oscillation
• Low voltage

Probe design.

• Non-corrosive / interactive

• Geometry

• Two probe vs. four probe

• Mitigating external fields

• Toroidal probe design

• https://publiclab.org/notes/bhickman/05-09-2016/conductivity-and-temperature-meter

• https://publiclab.org/notes/mathew/02-10-2016/riffle-conductivity-caps-and-other-housing-ideas

Temperature compensation.

Calibration techniques

Commercial standard solutions.

• http://www.davis.com/Product/Oakton_conductivity_solution_2764_S/YX-00653-20?referred_id=3388&gclid=Cj0KEQiArou2BRDcoN_c6NDI3oMBEiQANeix5up7px8eL9rByANeftTaCMyJusFlYSJtDb5ElptPo_AaAiaH8P8HAQ

DIY options.

• Saline solution
• Soda
• Salt and distilled water

DIY sensor designs

Ben Gamari.

Ref: RIffle design, which includes conductivity sensor.

Coqui.

Design. https://publiclab.org/wiki/coqui https://publiclab.org/notes/donblair/09-30-2014/coqui-bbv1-0

Problems:

• https://publiclab.org/notes/donblair/01-07-2016/conductivity-sensing-open-questions

Ben Hickman.

• https://publiclab.org/notes/JSummers/11-21-2013/conductivity-meter
• https://publiclab.org/notes/bhickman/05-09-2016/conductivity-and-temperature-meter

Sparky's Widgets.

• http://hackaday.com/2014/11/10/accurately-measuring-electrical-conductivity/
• https://github.com/SparkysWidgets/MinieCHW

openCTD.

openCTD project https://github.com/OceanographyforEveryone/OpenCTD http://oceanographyforeveryone.com/

Atlas Scientific conductivity circuit

Vintage.

http://www.ullasmann.eu/Doc/Salt_Concentration_Meter.pdf

Research directions

Research Notes on Public Lab

All research notes tagged 'conductivity':

• https://publiclab.org/tag/conductivity

'Coqui' approach:

• https://publiclab.org/wiki/coqui
• https://publiclab.org/wiki/555-conductivity-meter
• https://publiclab.org/notes/donblair/07-11-2014/simple-555-conductivity-meter
• https://publiclab.org/wiki/coqui-a-simple-water-conductivity-sensor
• https://publiclab.org/notes/donblair/01-07-2016/conductivity-sensing-open-questions
• https://publiclab.org/notes/rebeccah/08-29-2016/riffle-device-water-conductivity-sensor
• https://publiclab.org/notes/donblair/09-30-2014/making-a-diy-conductivity-probe-from-a-water-bottle-and-metal-screws

Jack Summers, Ben Hickman:

• https://publiclab.org/notes/bhickman/05-09-2016/conductivity-and-temperature-meter
• https://publiclab.org/notes/JSummers/11-21-2013/conductivity-meter

Patrick Hixenbaugh:

• https://publiclab.org/notes/pdhixenbaugh/08-20-2016/planning-for-a-new-riffle-conductivity-circuit

General:

• https://publiclab.org/notes/markwh/10-29-2014/calibrating-arduino-based-conductivity-meter
• https://publiclab.org/notes/donblair/06-18-2014/using-an-audio-jack-to-assess-conductivity

References

• http://mediashift.org/2012/04/water-hackathon-aims-to-understand-brooklyns-water-pollution096/

Guides to conductivity

• http://www2.latech.edu/~dehall/LWTL/ENGR121/notes/3_conductivity_sensor_intro.pdf
• https://www.snowpure.com/docs/FAQ_Conductivity_Thornton.pdf
• Fondriest : http://www.fondriest.com/environmental-measurements/parameters/water-quality/conductivity-salinity-tds/
• http://www.analytical-chemistry.uoc.gr/files/items/6/618/agwgimometria_2.pdf
• http://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/3130en.pdf
• https://www.pasco.com/support/technical-support/technote/techIDlookup.cfm?TechNoteID=514
• http://www1.udel.edu/pchem/C446/Experiments/exp4.pdf

References for conductivity levels

• http://www.mbhes.com/conductivity_measurement.htm
• Relationship between conductivity and water quality: http://www.lenntech.com/applications/ultrapure/conductivity/water-conductivity.htm