Mr.Freeze inside Effects

[DFW333]

Originally Posted by JStroop

It also trips some fire prevention systems, which we learned after some serious trial and error with Runaway Mountain, which used a laser beam system to detect smoke. The mine car on the facade that would occaionally roll out with a blast of fake smoke... if the wind was out of the East (a rare occasion for the metroplex... prevailing winds are usually out of the Southwest) when the mine cart rolled out with the accompanying blast of smoke, the wind would blow it right back inside the building... and trip the laser detectors.

There was a day where the ride kept going code 2 for fire alarm but nobody could figure out why. Finally, I was standing outside with Mike Apple and we were discussing what was going on, what to do about it (shut the ride down entirely, put that particular detector on 'test' mode so it wouldn't trip the system, blah blah blah... then I happened to be looking up at where the mine car came out of the facade and saw that the blast of fake smoke went straight into the hole and back inside the building. 5 seconds later, the fire alarm was sounding again.

My theory wasn't immediately accepted, but I told them to reset the system, and wait for the mine cart to come out again... sure enough 5 seconds later, the system sounded again.

Long story short, fake smoke is really cool, but it causes problems for sophisticated ride safety systems.

The fake smoke was operating again on Runaway Mountain this year. They must have moved the detector out of range of the smoke or changed the formula used in the smoke machine.

[Twisted]

Originally Posted by DFW333

The fake smoke was operating again on Runaway Mountain this year. They must have moved the detector out of range of the smoke or changed the formula used in the smoke machine.

Perhaps they moved the detector or found a way to block the building to allow the chemical fog into the building itself. The laser detection system is based on blocking the beam itself since micro-particles show up the same, whether real smoke or chemical-based. Most home-based smoke detectors operate on the same system. Another possible solution is to install heat-detectors so breaking the beam isn't the basis for setting the system off. Or it could simply be, as Jeremy mentioned, that it was a rare occurance that the wind blew the fog back into the facade, thus they could simply shut off the fog machine.

[DFW333]

There's 2 types of smoke detectors, the photoelectric type and ionization type, which style is used at SFOT? I dont think anyone here knows.

Ionization Detectors
Ionization detectors have an ionization chamber and a source of ionizing radiation. The source of ionizing radiation is a minute quantity of americium-241 (perhaps 1/5000th of a gram), which is a source of alpha particles (helium nuclei). The ionization chamber consists of two plates separated by about a centimeter. The battery applies a voltage to the plates, charging one plate positive and the other plate negative. Alpha particles constantly released by the americium knock electrons off of the atoms in the air, ionizing the oxygen and nitrogen atoms in the chamber. The positively-charged oxygen and nitrogen atoms are attracted to the negative plate and the electrons are attracted to the positive plate, generating a small, continuous electric current. When smoke enters the ionization chamber, the smoke particles attach to the ions and neutralize them, so they do not reach the plate. The drop in current between the plates triggers the alarm.

Photoelectric Detectors
In one type of photoelectric device, smoke can block a light beam. In this case, the reduction in light reaching a photocell sets off the alarm. In the most common type of photoelectric unit, however, light is scattered by smoke particles onto a photocell, initiating an alarm. In this type of detector there is a T-shaped chamber with a light-emitting diode (LED) that shoots a beam of light across the horizontal bar of the T. A photocell, positioned at the bottom of the vertical base of the T, generates a current when it is exposed to light. Under smoke-free conditions, the light beam crosses the top of the T in an uninterrupted straight line, not striking the photocell positioned at a right angle below the beam. When smoke is present, the light is scattered by smoke particles, and some of the light is directed down the vertical part of the T to strike the photocell. When sufficient light hits the cell, the current triggers the alarm.

Which Method is Better?
Both ionization and photoelectric detectors are effective smoke sensors. Both types of smoke detectors must pass the same test to be certified as UL smoke detectors. Ionization detectors respond more quickly to flaming fires with smaller combustion particles; photoelectric detectors respond more quickly to smoldering fires. In either type of detector, steam or high humidity can lead to condensation on the circuit board and sensor, causing the alarm to sound. Ionization detectors are less expensive than photoelectric detectors, but some users purposely disable them because they are more likely to sound an alarm from normal cooking due to their sensitivity to minute smoke particles. However, ionization detectors have a degree of built-in security not inherent to photoelectric detectors. When the battery starts to fail in an ionization detector, the ion current falls and the alarm sounds, warning that it is time to change the battery before the detector becomes ineffective. Back-up batteries may be used for photoelectric detectors.

[thecloak]

We didn't use smoke detectors on side 4 this year. We just had Merv keep an eye out.

[VanceCope]

Originally Posted by DFW333

When the battery starts to fail in an ionization detector, the ion current falls and the alarm sounds, warning that it is time to change the battery before the detector becomes ineffective.

of course mine always seem to fail in the middle of the night, and there is nothing more annoying than that beep a detector makes, and of course it's always the one you have o have the ladder/step stool for

[thecloak]

Ah yes, but you can't use a ladder until you have been certified -- to not fall off.