Sandhill Park Mental Hospital, Nr. Taunton.

[RichardB]

Passive Infra Red I think. It's a sensor that can detect movement, as seen on crappy Halogen security lights.

 

[JulesP]

Passive Infra Red I think. It's a sensor that can detect movement, as seen on crappy Halogen security lights.

And alarms

 

[GeorgieKirrin]

This looks like a great explore - I love that pic of the toilet. All the greenery makes it look like the cleanest bog in the world!

 

[lilli]

The fire engine is no longer there!

 

[FieldyM]

plz may i ask wot 'pir' is plz?

as you ask i second that, what is PIR?

A Pyroelectric InfraRed sensor (PIR sensor) is an electronic device that measures infrared (IR) light radiating from objects in its field of view. Because it does not emit any energy, it is often mistakenly called a Passive Infrared Sensor. PIR sensors are often used in the construction of PIR-based motion detectors (see below). Apparent motion is detected when an infrared source with one temperature, such as a human, passes in front of an infrared source with another temperature, such as a wall.

All objects emit what is known as black body radiation. It is usually infrared radiation that is invisible to the human eye but can be detected by electronic devices designed for such a purpose. The term passive in this instance means that the PIR device does not emit an infrared beam but merely passively accepts incoming infrared radiation.

The PID can be thought of as a kind of infrared camera that remembers the amount of infrared energy focused on its surface. Once power is applied to the PID, the electronics in the PID shortly settle into a quiescent state and energize a small relay. This relay controls a set of electrical contacts that are usually connected to the detection input of a burglar alarm control panel. If the amount of infrared energy focused on the pyroelectric sensor changes within a configured time period, the device will switch the state of the alarm relay. The alarm relay is typically a "normally closed (NC)" relay, also known as a "Form B" relay.

A person entering a monitored area is detected when the infrared energy emitted from the intruder's body is focused by a Fresnel lens or a mirror segment and overlaps a section on the chip that had previously been looking at some much cooler part of the protected area. That portion of the chip is now much warmer than when the intruder wasn't there. As the intruder moves, so does the hot spot on the surface of the chip. This moving hot spot causes the electronics connected to the chip to de-energize the relay, operating its contacts, thereby activating the detection input on the alarm control panel. Conversely, if an intruder were to try to defeat a PID, perhaps by holding some sort of thermal shield between himself and the PID, a corresponding 'cold' spot moving across the face of the chip will also cause the relay to de-energize — unless the thermal shield has the same temperature as the objects behind it.

 

[Potter]

That looks a fantastic place.

I wonder where the fire engine has gone and who's took it?

I would love to explore this one.

 

[Evilgenius]

The fire engine has gone? I was up there a few months ago and it was there, i think to move it would be a hell of a job to!

 

[dangerous dave]

we had a look about n did not see it

 

[markymark1]

Passive Infra Red I think. It's a sensor that can detect movement, as seen on crappy Halogen security lights.

when i was last in there (late last year) there was only 1 that was working which was down stairs to the left of the main entrance. 10 mins later a short bloke (and dog ) came rushing up the road and burst in on us.basically said to leave the police are on the way.they never showed tho but we left as asked

 

[magoo²]

Loving that fire engine nice one