How to measure conductivity ?

[abhimanyu143]

Hello ,

I need help I want make automated system using micro controller that will measure the conductivity of many nutrient
How to measure conductivity of nutrient that are in water ?

Microcontroller
multimeter
battery 12 v dc
glass water
Nitrogen
Phosphorous
two electrode

I am using micro controller, two pins of microcontroller are connected with two electrode
just for example I have 1 glass of water with Nitrogen than I can measure conductivity of Nitrogen . but If I use 1 glass water with Nitrogen and Phosphorous then how can I measure conductivity of two nutrient with two electrodes that are connected with microcontroller?

we have only two electrode pins that are measuring conductivity of many nutrient I am not sure that the two electrode can measure conductivity of many nutrient .

I can measure conductivity of single nutrient but the question is how to measure conductivity of different nutrients that are in water ?

 

[Harald Kapp]

You can only measure the conductivity of the solution as a whole. You will not be able to separate the conductivities of different elements solved in water. If you need to determine the conductivity of different materials you will have to provide separate solutions and measure each separately.

just for example I have 1 glass of water with Nitrogen than I can measure conductivity of Nitrogen

You will not measure the conductivity of nitrogen but the conductivity of water. I think you probably do not mean pure nitrogen (or phosphorus in your second example) but some salt of these elements, solved in water.
If you really want to measure the conductivity of pure nitrogen or phosphorus, you will need the pure elements, not a solution in water. This will be difficult, to say the least, as nitrogen is a gas and becomes liquid only below -195.8 °C whereas phosphorus is solid and will melt only above 280.5 °C

You will most probably also need a suitable so called analog front end (amplifier, filter) to process the weak signal from the electrodes such that the microcontroller will be able to convert it to a digital signal (using an A/D-converter, either separate or built-in) and process the digitized values.

 

[shrtrnd]

There are plenty of manufacturers who make conductivity measurement devices. I'd be looking at one of those unless this is a design question.

 

[abhimanyu143]

You can only measure the conductivity of the solution as a whole. You will not be able to separate the conductivities of different elements solved in water. If you need to determine the conductivity of different materials you will have to provide separate solutions and measure each separately.


You will not measure the conductivity of nitrogen but the conductivity of water. I think you probably do not mean pure nitrogen (or phosphorus in your second example) but some salt of these elements, solved in water.
If you really want to measure the conductivity of pure nitrogen or phosphorus, you will need the pure elements, not a solution in water. This will be difficult, to say the least, as nitrogen is a gas and becomes liquid only below -195.8 °C whereas phosphorus is solid and will melt only above 280.5 °C

You will most probably also need a suitable so called analog front end (amplifier, filter) to process the weak signal from the electrodes such that the microcontroller will be able to convert it to a digital signal (using an A/D-converter, either separate or built-in) and process the digitized values.

I want to grow plant in mixed of liquid nutrient and water
Plant growing in water

Requirement
Water
Fertilizer

Best time to Fertilize
Plant grow from seed we need to Fertilizer plant after their active growth
For better growth , we need to provide right Fertilizer at right time on basis of plant sie , weather, deases
Example- on the basis of plant size
Small plant need less Fertilizer
Large plant need more Fertilizer

Its all about agriculture site

Now from electronics site. I want to make automated system that take decision , Add more or less Fertilizer into water . If the plant require less or more Fertilizer the system can adjust itself
That’s why I am using microcontroller Ic How to make automated system that will take decision Add more or less Fertilizer into water?

 

[shrtrnd]

That's called hydroponics. Google it and you'll get hits on all kinds of advice and companies involved in this.

 

[abhimanyu143]

we can measure conductivity of whole solution. we can't measure separate the conductivities of different nutrient solved in water
for example we can not measure the separate conductivity of potassium (K), phosphorus (P) and nitrogen (N). but we can measure conductivity of whole solution In water.
I can't buy conductivity sensor .how to measure conductivity of whole solution in water without conductivity sensor ?
I have listed some component That can I use
water , NPK Fertilizer ,multimeter , two electrodes

 

[abhimanyu143]

we can measure conductivity of whole solution. we can't measure separate the conductivities of different nutrient solved in water
for example we can not measure the separate conductivity of potassium (K), phosphorus (P) and nitrogen (N). but we can measure conductivity of whole solution In water.
I can't buy conductivity sensor .how to measure conductivity of whole solution in water without conductivity sensor ?
I have listed some component That can I use
water , NPK Fertilizer ,multimeter , two electrodes

Please help me I am not understanding how to make electronic circuit for automatic hydroponic system using microcontroller

 

[Harald Kapp]

This may be a good read for you and your project.

 

[abhimanyu143]

home made conductivity sensor
specification
two copper wires
two platinum electrode

I am not sure. Does it work for conductivity ?

 

[abhimanyu143]

automated hydroponic plant system that will sense condition(conductivity of water ) and provide sufficient Mineral Nutrients for growing hydroponic plant.

we place the seed into water, seed grow into water , growth should start after 2 or 3 weeks.we don’t feed fertilizer until the first set of true leaves appears When seeding develop their true leaves and roots. Its time to feeding fertilize.we need to provide right fertilizer for good growth
Most common fertilizer is NPK, after two or three weak or after the first set of true leaves apper we need to fertilize plant. Fertilize approx every two weeks

Automated system (small and low cost system)
Parameter – conductivity

Project part list
Electrodes probes
Micorcontroller
Amplifier or filter
Resistor
A to D converter Ic
Volve or relay

Automated system that Add more or less fertilizer into water ,that maintain conductivity range

fertilize plant after their active growth ,after two or three weak or after the first set of true leaves apper we need to fertilize plant
ADD small value of NPK into water because small plant take less fertilizer
After two weeks Add large value of NPK into water because large plant take large fertilizer

I want to make Automated system that will Add more or less fertilizer into water
If plant need more or less fertilizer system will adjust itself

If you need more Information to help me, please ask me