Light Dependent Resistor in water

In summary, the conversation is discussing the resistance of a Light Dependent Resistor (LDR) to water and the potential problems that could arise if it is exposed to water directly. The possibility of using a test tube to protect the LDR from water is also mentioned, but there are concerns about the wires becoming wet. The idea of using a LDR inside a pipe with LED lights is also mentioned.
  • #1
mathew086
42
0
Is a Light Dependent Resistor (LDR) resistant to water? Will there be any problems if it is exposed to water directly?
 
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  • #2
They look fairly well sealed but I'd worry about insulating the wires.

Could you put it in a test tube or something similar?
 
  • #3
The insulating wires will not be exposed to water. Just the LDR head will be exposed to water.

If inserted inside a testube, the light intensity received will be further reduced , right? or no??
 
  • #4
The only CdS cells I have seen would be hard to immerse in water without getting the wires wet. They are small and quite thin.

Test tube glass would be pretty good at transmitting visible light, I think, but I haven't measured this. They look like they transmit light very well.
Easy to check if you already have a LDR.
Thin soda glass test tubes are cheap and would be worth a try.

What are you trying to do?
 
  • #5
I am having a pipe. I am planning to put an array or LEDs on one side and the LDR on the opposite side ( inside the pipe). So planning to bore a small hole in the size of head of LDR and keeping just that head inside the pipe.
 

1. What is a Light Dependent Resistor (LDR)?

An LDR is an electronic component that changes its resistance in response to changes in light intensity. It is also known as a photoresistor because it is sensitive to light.

2. How does an LDR work?

An LDR is made of a semiconductor material with a high resistance that decreases when exposed to light. When light hits the LDR, photons excite the electrons in the material, causing them to move and decrease resistance. The more light that hits the LDR, the lower its resistance.

3. What happens when an LDR is placed in water?

When an LDR is placed in water, the water acts as a conductor and allows electricity to flow through it. This changes the resistance of the LDR, making it less sensitive to light. The more submerged the LDR is in water, the lower its resistance will be.

4. What applications does an LDR in water have?

An LDR in water can be used for detecting water levels, monitoring water quality, and controlling water pumps. It can also be used in underwater photography and aquarium lighting systems.

5. Are there any limitations to using an LDR in water?

Yes, there are a few limitations to using an LDR in water. The water must be relatively clean and free of contaminants for accurate readings. The LDR may also corrode over time if not properly sealed. Additionally, the LDR's sensitivity to light may vary depending on the type and intensity of the light source.

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