On 29/11/2019 01:23, ss wrote:
I am hoping to use a cheap PIR to monitor outdoor activity at night, but
the one I have appears to be too sensitive, it doesnt have the usual
adjustments so may try and block some of the lense range.
Anyhow I opened it up and there is a sensor and then an LED `bulb` which
comes on when activated.Â* Is the LED light necessary for it to operate
as I would prefer it didnt light up if someone is snooping around my
back garden at night.

No the LED is to indicate the thing has triggered. A spot of black paint
will stop it being visible whilst retaining whatever IP rating it has.

Be aware that it will trigger on spider inside or bats flying close to
the sensor as well as rats, cats, foxes and badgers at increasing range.

It is a wirless battery operated cheapo whereby the sensor is in the
garden and the receiver is wireless in the house.

A wildlife PIR triggered camera might be more useful for your
application - that way you have some video of the scrotes.

--
Regards,
Martin Brown