How to correctly meaure an LDR?

[orbiter]

Hiya fellas,

Got some new light dependant resistors today in a variety type pack, so they're not rated, so... How do I measure them correctly please?

Is it in total darkness, shade... Or some sort of average?

Thanks guys

regards

orb

[PeterG]

Are there any markings on it at all?

This webpage may be a good starting point.
http://www.technologystudent.com/elec1/ldr1.htm

Regards

[orbiter]

Are there any markings on it at all?

This webpage may be a good starting point.
http://www.technologystudent.com/elec1/ldr1.htm

Regards

No mate, I've checked all of them. No markings at all

They're just the very basic type, similar to This LDR and are measuring a dark resistance of around 500k, now this could be pretty close I guess, but I'm not sure if just putting a rag over the end of them, then measuring the resistance is an efficient way of doing it?

regards

orb

[NiHaoMike]

Put it into a box with a LED and a reference sensor. Vary the LED brightness and note the changes.

[orbiter]

Put it into a box with a LED and a reference sensor. Vary the LED brightness and note the changes.

Thanks Mike. Is that a legitimate & accurate way of measuring them?

Regards

orb