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Is hand sanitizer electrically conductive ?

Audioguru

Sep 24, 2016
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Circuits that are used to detect when the water level is low for plants use AC, not DC. DC causes plating and corrosion of the probes.
 

Bluejets

Oct 5, 2014
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I'm planning to build a DC based transistor switch using my arduino for detecting the sanitizer level in the tank. Using the following example, http://www.circuitstoday.com/water-level-controller-using-arduino .

My question is if sanitizer (70% alcohol) would be conductive for my design to work ?

A capacitive sensor may do the job.

I have read where it is necessary to seal the edge of the sensor board with a bit of epoxy though, as the manufacturer missed that bit.

https://www.ebay.com.au/itm/Corrosi...653096?hash=item3428040b68:g:Si4AAOSwj3NevI0V

Example video with Arduino code below.....


 

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KMoffett

Jan 21, 2009
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Per Audioguru's advice, this a version of a water level indicator circuit that I've used several times. Take the 4093's outputs to your Arduino's inputs. But don't know about sanitizers conductivity.WaterLevelX6A.gif
 

Alec_t

Jul 7, 2015
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My question is if sanitizer (70% alcohol) would be conductive for my design to work ?
It depends on the ingredients in the product. A bottle I have lists the ingredients as "Alcohol denat, aqua, glycerin, propylene glycol, triethanolamine, carbomer, aloe barbadensis gel, tocopheryl acetate, parfum". My multimeter with probes ~ 1cm apart in a small puddle of it shows a resistance of about 0.5 megohms.
 
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KMoffett

Jan 21, 2009
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No. The dielectric is an insulator. Well, the two plates of a capacitor in this case case must be insulated. The dielectric constant of the electrode insulation and that of the liquid and air determine the capacitance sensed.
 

Harald Kapp

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Circuits that are used to detect when the water level is low for plants use AC, not DC. DC causes plating and corrosion of the probes.
AC is definitely preferred over DC.

Regardless of AC or DC an electric current through a liquid can always lead to decomposition of the fluid contents. Some possible results are:
  • dangerous substances as a result of decomposition
  • loss of effectivity of the sanitizer (in this particular case) due to decomposition of its active ingredients

I do recommend the capacitive solutins proposed.
Or, if you need to sense only when the level falls below a certain threshold you may use a float lever with a switch attached. Or use the optical properties of the liquid and sense the level with an LED and a phototransistor.
 

KMoffett

Jan 21, 2009
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To add to Alec_t's suggestion, post a photo of the tank you were planning to use?
 
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