Light monitor sysrem

how much area covered by LDR for light intensity.

@jigarprajapati240120 The LDR measures local light intensity i.e., light that is falling on it directly.

In our project we have used a miniature low cost LDR of 5 mm. This one detects the intensity of light closer to it. As the diameter increases the area of detection increases.

1 Like

In our project ,we have used the LDR covers the range 5mm. LDR is a resistor whose resistance varies inversely with the amount of light falling on it. When it’s dark, LDR has high resistance known as dark resistance. Usually, LDR has dark resistance will be in the range of mega ohms. When light falls on LDR, resistance reduce to kilo ohms range.

The most common type of LDR has a resistance that falls with an increase in the light intensity falling upon the device . The resistance of an LDR may typically have the following resistances:

Daylight

= 5000Ω

Dark

= 20000000Ω