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Traffic Pre-emption strobe lens color question
Posted: Wed Feb 04, 2004 10:39 pm
by 007
I've got a Nova "Mircodash" self-contained 20 watt pre-emption strobe, with a clear lens. Due to in-car video camera backflash considerations, I'd like to change the lens color from clear to either red or blue. This light will be making its' rounds in multiple cars, as a beta test.
Will the light still work as a pre-emption emitter with the lens color being something other than clear? It could even be amber for all I care, so long as it's not clear. The preferred color is blue, if it makes a difference....
Thoughts?
Posted: Thu Feb 05, 2004 12:35 am
by Aces-Warehouse
color doesnt normally make a difference.... but the problem comes in if the color is too thick you wont have good responce. Remember it needs to see the light in order to work. They make IR models where no light is emmited visable to the eye.
Posted: Thu Feb 05, 2004 12:41 am
by 007
IR would be the way to go, but with us $$ is going to prevent that. This was a gimme, and we are going to see if it is efficent and/or cost-effective...
Posted: Thu Feb 05, 2004 5:49 am
by FFParamedic571
Ive seen them mounted in a bar with a red dome . Not being clear cuts down on the range. It still works but the distance is reduced..
Posted: Thu Feb 05, 2004 1:04 pm
by Cam
You will lose range. If I recall right, amber would be the best, then blue then green and last would be red. You may want to fine out about using amber to the front, it's not aways allowed in an EV.
Posted: Thu Feb 05, 2004 4:04 pm
by KitN1MCC
just be carefule with that light i do not belive it has bine apporved by 3M
Posted: Thu Feb 05, 2004 5:35 pm
by Code3Response
Has anyone found a source for the infrared lenses for the Microdash? Im a dealer for Nova and cant even get a straight answer!

Posted: Thu Feb 05, 2004 8:40 pm
by tvsjr
Cam22 wrote:You will lose range. If I recall right, amber would be the best, then blue then green and last would be red. You may want to fine out about using amber to the front, it's not aways allowed in an EV.
I believe blue is actually the most saturated/least transmissive. Also, preemption devices are known to "see" IR, and red is closest to IR...
Posted: Thu Feb 05, 2004 9:01 pm
by 007
Thanks guys....will track down a red dome and do some testing with it at an out of the way intersection. I'll post the results when I get them.
Posted: Thu Feb 05, 2004 9:14 pm
by jim
Make sure the photo receiver is for visible light- not strictly for receiving the IR transmitters, which are a cluster of high-powered IR LEDs on some systems.
Posted: Fri Feb 06, 2004 3:44 pm
by jedi_saber
Ok, bear with me please. As someone who has used the 3M opticom IR system before, I am a bit confused about all these new aftermarket emitters such as those from tomar, MIRT and now Nova.
My understanding was that it is based on IR... But I was always intrigued by the fact that the 3M emitter always looked like a fast paced, almost Neobe looking strobe...
Now having seen pictures of the much cheaper versions that Nova, Tomar and MIRT make, it looks like these are strobes that flash at the respective rates (believe it's 14fps for EVs). All these manufacturer's claim that they are compatible with the 3M brand controlled intersections.
Can somebody please explain to me how the system works? If it is strobe or actually IR controlled...I was under the impression that the opticom system actually had a way of logging individual units passing the intersection and such, but that would require data to be sent as well...
Posted: Fri Feb 06, 2004 4:05 pm
by apco25
The Opticon system we use out here has 3x7 TOMAR emitter heads. Everthing is clearly label pre-emption strobe. The flash pattern is in visible light, clear in this instance and at a pretty high FPS.
I don't know of anyone using the IR version. We do have one town that had to be different. They use an RF based system for their units and the visible emitter receiver for mutual aid.
Posted: Sat Feb 07, 2004 7:13 am
by USPSS
I have a TOMAR IR emitter that works well, I used it when I was living in Phoenix many years ago. I have since given it to a Chief friend in the Phoenix area and he uses it and loves it. The IR units work very well, this is a handheld unit.
Opticom
Posted: Sat Feb 07, 2004 7:27 am
by fd2119
[post removed]
Posted: Sat Feb 07, 2004 8:26 pm
by savtru
OK...Let me CLEAR this up for ALL OF YOU. 3M Opticom and Tomar Preemption sensors ALL read IR signals. You can use a IR filter or NO filter and they will still work. BUT the IR filter will limit the IR signal to about half of the distance of a NON filtered unit. The TOMAR, 3M and NOVA units all use the same technoligy to creat the signal. CRYSTAL LOCKED TIMING creates the signal, so for those people who think flashing your headlights will work, NOT.
PLEASE REMEMBER THOUGH...ALL PREEMPTION emitters are FEDERALY regulated and if you get caught, GOOD LUCK. Here in CA they use 3M and I use Tomar with IR filter and it works great.
Posted: Sat Feb 07, 2004 8:51 pm
by Cam
I love how people always add in the "3 letter" no matter what topic or even if it's true. The fed (or anyone for that matter) can't just start using something different when it comes to preemption, and it would only work on lights that the city or state has set up for it to work with. They could use IR, as could anyone. The systems has a rate of 10 and 14 fps.
As far as I know, preemption emitter are not federaly regulated. Feel free to prove me wrong here.
Posted: Sat Feb 07, 2004 8:52 pm
by 007
Who said anything about flashing your highbeams?
Posted: Sat Feb 07, 2004 9:41 pm
by jim
They aren't Federally regulated. Myself, as a Tomar distributor, just needs legit proof of WHY, WHO and WHERE they are going. According to the manufaturer, they can only be sold to a municipality or traffic signal service.
I can order one tomorrow with no problems, which proves the feds have nothing to do with it.
And no....I won't get one for anybody!
Posted: Sat Feb 07, 2004 10:59 pm
by 007
You gotta love the newbie know-it-all's....

Posted: Sat Feb 07, 2004 11:26 pm
by ExKa|iBuR
Well, there are local regulations regarding their use. Here in Ontario, using a traffic preemption device is illegal unless you are a repair person while repairing a lamp, or emergency vehicles.
3M's website says that it needs a special emitter that transmits a special code or some such....that's not true. A RadioShack strobe light is enough to set these things off. I know someone that modified a RadioShack strobe, put 3 or 4 strobe tubes in it..to get very fast flashes, and it worked fine...a little TOO fine.
-Mike
Posted: Sun Feb 08, 2004 5:26 am
by Aces-Warehouse
Strobes flashing at certain rates can set them off yes. UNLESS you're county/state/whatever has them encoded for SPECIFIC Flash rates via Crystal controlled Emmitters/Receivers. So if they work without the "specific crystal/flash rate" you're lucky for now. They won't for long.
Posted: Sun Feb 08, 2004 6:24 am
by FFParamedic571
Jim's right.. they are listed as" RESTRICTED ITEM
The sale of this item is restricted to state and local governments and to authorized distributors only. "right off the Tomar website.
Illinois made it a law that private individuals can have up to a $1000 fine if caught with one thanks to morons selling homebrews on ebay..
Posted: Wed Feb 11, 2004 4:40 am
by savtru
MAN people are QUICK to insault others on here. The funny thing about my comment on FEDS and the law, here in CA the FEDS are who file charges against those who get caught with preemption emmitters. Why is this? Just thought I would ask! You know I'm a NEWBIE......NOT!
Posted: Wed Feb 25, 2004 8:31 pm
by Bob W
ExKa|iBuR wrote:Well, there are local regulations regarding their use. Here in Ontario, using a traffic preemption device is illegal unless you are a repair person while repairing a lamp, or emergency vehicles.
3M's website says that it needs a special emitter that transmits a special code or some such....that's not true. A RadioShack strobe light is enough to set these things off. I know someone that modified a RadioShack strobe, put 3 or 4 strobe tubes in it..to get very fast flashes, and it worked fine...a little TOO fine.
-Mike
Actually, there is a version of Opticom that IS coded. With "normal" Opticom - like the one you successfully triggered - there can be two priority levels. High priority, where the flash rate is around 14 flashes per second, usually results in the signal changing pretty close to instantly. This is used on emergency vehicles. Low priority is used on buses. It's flash rate is around 9 flashes per second. If allowed in the signal controller, it just makes the phase (delay before change) alot shorter.
Coded embeds a unit ID in the flash stream. The flash rate is effectively doubled, and every other flash may, or may not be present.
Here's 14 FPS in non-coded mode:
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
Here's 14 FPS with an ID of 154 coded in it:
X X X XXX XXX XXX XXX X X X X XXX XXX X XXX XXX XX
The rate of the encoded example would be about 28 FPS if ALL flash timeslots were filled. To decode the above example, remember 8 4 2 1, and look at the filled slots.
Posted: Wed Feb 25, 2004 9:11 pm
by Cam
FFParamedic571 wrote:Jim's right.. they are listed as" RESTRICTED ITEM
The sale of this item is restricted to state and local governments and to authorized distributors only. "right off the Tomar website.
Illinois made it a law that private individuals can have up to a $1000 fine if caught with one thanks to morons selling homebrews on ebay..
Yes, Tomar restrictes who they sell them to. Has nothing to do with any government or "3-letter" Cowthief.
Posted: Wed Feb 25, 2004 9:13 pm
by Cam
savtru wrote:MAN people are QUICK to insault others on here. The funny thing about my comment on FEDS and the law, here in CA the FEDS are who file charges against those who get caught with preemption emmitters. Why is this? Just thought I would ask! You know I'm a NEWBIE......NOT!
What do the "FEDS" charge them with? In most cases it's the local, country or state that does traffic laws, not the federal government.
Cam
preemption
Posted: Thu Feb 26, 2004 10:57 pm
by Mike in CT
In good ol Connecticut its simple, you get caught, you get charged with
tampering with a traffic control device (comes in under the criminal mischief section).
If it is a serious thing, like you cause an accident, or the prosecutor is sharp, you can conceivably get nailed for
reckless endangerment
interfering with a Firefighter / Police officer
or if its a fatality... hire a good homicide defense attorney.
-----
and on a lighter note...
Someone told our Firechief that his brandy new preemption system can be taken over by a TV remote... (this is gonna be a good one!...film at 11...)
Mike in CT