Light Dependent Resistor in water

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Discussion Overview

The discussion revolves around the suitability of Light Dependent Resistors (LDRs) for use in water, specifically addressing concerns about their water resistance and the implications of light transmission when placed in a test tube or similar container. The context includes practical applications and experimental setups involving LDRs and LEDs.

Discussion Character

  • Exploratory, Technical explanation, Experimental/applied

Main Points Raised

  • One participant questions whether LDRs are resistant to water and if direct exposure would cause problems.
  • Another participant suggests that while the LDRs appear well sealed, there may be concerns regarding the insulation of the wires.
  • A participant proposes using a test tube to contain the LDR, raising a question about whether this would reduce the light intensity received by the LDR.
  • Concerns are expressed about the difficulty of immersing certain types of CdS cells in water without wetting the wires, noting their small size.
  • There is a suggestion that test tube glass may transmit visible light effectively, although this has not been measured by the participants.
  • A participant shares their intention to create a setup with LEDs on one side of a pipe and the LDR on the opposite side, indicating plans to modify the pipe to accommodate the LDR head.

Areas of Agreement / Disagreement

Participants express varying levels of concern regarding the water resistance of LDRs and the impact of using a test tube on light intensity. There is no consensus on the best approach or the implications of the proposed setups.

Contextual Notes

Participants have not reached a conclusion about the water resistance of LDRs, the effectiveness of test tube glass in transmitting light, or the overall feasibility of the proposed experimental setup.

mathew086
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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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They look fairly well sealed but I'd worry about insulating the wires.

Could you put it in a test tube or something similar?
 
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??
 
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?
 
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.
 

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