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# "Burning Power" unit of measurement please?

#### Meatball

##### New member
It is pretty well known around here that a 200mw blu ray laser, is going to burn a heck of a lot better than a 200mw red laser.

So if this is even a possibility, I would like to propose a forum- wide unit of measurement, it should indicate "energy intensity". I figure that the more "intense" the energy emitted from the laser (or the energy density) (no matter its wavelength), the better the energy is applied to a target, (the more work is done). If you think about it, its pretty simple. This unit should incorporate BOTH the wavelength of the laser as well as its optical "power", which makes this unit a bit more useful when comparing any number of lasers together, same color, or differing.

I propose that in order to measure the energy intensity of any given laser, we use a quite simple process that anyone can perform. Suppose 10 or so layers of electrical tape (black only since it cares not of wavelength) are held in front of a laser at a focused length of 1 foot. Now, before I continue, it must be noted that this procedure can result in 2-3 output units.

We can measure the amount of time in seconds, that it takes for the laser to completely penetrate the 10 layers. We can use seconds as a burning period, where smaller quantities indicate a more powerful laser.

or take its reciprocal....

We can use the layers of electrical tape as the dependent variable, and the time as the controlled variable. Taking a standardized unit of time (10 sec), and then measure the number of complete layers of electrical tape that have been completely burned through (where there is a hole when it is held up against a light). This number of layers would again, be quite universal, where larger quantities indicate a more powerful laser. However, it would not be as accurate, OR precise as the previous method.

OR

We could get a bit more complicated, and add a little bit of math to it all, by simply combining the two above methods into a rate. Layers/time. Where the unit of measurement (like in the top method) would be a unit of time (sec). The only difference would be that the denominator would always be over 1. We could then get a speed of burning, in not just Layers/Time, but in something more universal like Layers/sec. A typical quantity of measurement for this unit would mostly likely be a decimal, easily rounded into hundredths or so.

Do you guys think we can do it? Layers/sec

EDIT: Make that Layers/sec/foot. Or Foot-layers/sec

I think it could be a very easy, and consistent method for measuring up a laser against another. Please don't hesitate to say what you really want to about this idea. Heck, its probably not even an original idea. But its worth a shot. What do you guys think?

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#### lasersbee

##### Well-known member
Not to shoot this idea down... but if the tests are not done by the same
individual with the same apparatus.. I could see a lot of variations...

The blackness...texture and thickness of the black tape... The amount and
chemical composition of the glue on the tape... the age of the tape..

But yes... I could see some other inexpensive way to measure the burning
power of a laser (not the raw optical output that is measured by a LPM)
A scale of sorts...

Jerry

#### sportcoupe

##### New member
Not all electrical tape is the same. Period. Your test needs something that is consistent. I can get cheap electrical tape from the "dollar store" and it is much thinner the a quality tape made by 3M for example. Ten layers of each would result in different test times with the same laser.

I can also see people "cheating" stating that they burned through in 3 seconds when it actually took 5 (example, not actual figures).

#### Meatball

##### New member
You guys have got a good point there. I had no idea that electrical tape would vary such much on a chemical composition level. I just kinda assumed that electrical tape was electrical tape, and that it was made only one way.

So if black electrical tape isn't universal enough for measurement, then what else might work in a similar fashion? What else is easy enough to get a hold of and use, that would work unconditionally? There's got to be something. Where are those creative minds of yours? We've got to be able to test diodes for their burning abilities, we've got to have a way to compare them scientifically, there must be a method.

We could burn through Oreo cookies... lol

SC, I can your point about people lying... though I suppose anybody here can (and probably do) already lie about their power outputs whether they have a meter or not. Nothing that can be controlled.

Laserbee: what other inexpensive way might you be thinking of? Just curious I guess.

#### Grix

##### New member

Ex: mW / 1000 * nm

#### Ash

##### New member

Ex: mW / 1000 * nm
I like this idea better. But, how accurate is it,..? And what units do we use? bp, burning power?

Calculating:
100mW/1000 x 405nm = 40.5bp (burning power)
200mW/1000 x 660nm = 132bp (burning power)
50mW/1000 x 532nm = 26.6bp (burning power)

Seems pretty accurate. :takeit:

#### YGG

##### New member
I would have to say that we could only conduct these tests with the same brand tape, not to easy I know, but we should have it so that you have a tape measure set to a common variable for all laser testing, the laser and tape are placed on a level surface with the tape not strected and a timer that you press start on the moment you start to burn. It may be a pain in the ass to factor all this in but it would be more acurate. Not sure what you would hold the tape with though.

#### Meatball

##### New member
math is always nice. But we ought to account for some of the factors that can affect a laser's ability to burn. Distance for one, would be difficult to incorporate into a simple equation unless someone has a bunch of formulas for us to work with. I'd like a scientific procedure to compare lasers. Theoretical comparisons are nice, but I just think that there could be a nasty mix up of other factors to have to consider.

#### YGG

##### New member
Like I said, measurements would have to be exact(no I didn't but I should have) and unforunatley some of the higher powers would just burn the crap out of the tape layers for ever, you could have a ridiculous amount of layers and they would keep burning, lasers don't just stop, this would have to be some complicated jibberish equation. Time is a good factor but some lasers just burn really fast, it would take to many layers to test every time.

#### Meatball

##### New member
We all know that 3M makes good quality tape, I'm sure their product is very consistently produced. (Which is why Oreo cookies might work just the same)

But since tape isn't as silly as Oreos, we'll try and "stick" with the tape.

I don't think there has to be much to the mounting of the tape. We're not cutting it, just penetrating it. All one should have to do is cut out 10 squares of the stuff, and stick each piece on top of one another. If we put gaps between each piece, the optimum focus will be lost way sooner.

Again, math would be nice, but I'm not sure how to count in time, numbers of layers burned through, wavelength, power output AND distance.

#### k1kb0t

##### New member
What about something other than tape? Paper maybe .. :anyone:

#### Meatball

##### New member
Like I said, measurements would have to be exact(no I didn't but I should have) and unforunatley some of the higher powers would just burn the crap out of the tape layers for ever, you could have a ridiculous amount of layers and they would keep burning, lasers don't just stop, this would have to be some complicated jibberish equation. Time is a good factor but some lasers just burn really fast, it would take to many layers to test every time.
You are too correct. Thats where the third method might come in handy. It would allow someone with a 350mw 8x blu ray, to layer 20 or even 50 pieces together. The more pieces that would be present, would make for a much more accurate calculation. You get more pieces of data with 50 layers, than you do with 10. 10 of course was just an example.

So that being said, to account for much more powerful lasers, more layers of electrical tape could be used.

Example, lets say an 350mw 8x owner wants to know his "burning power".

He layers up 30 pieces of 3M electrical tape, and times the period that it takes for the laser to peek it's violet light out the back side of the tape from one foot away. (he hold the 30 layers with a helping hands holder)

ex: He gets a time of 6.32 sec. (Wow!)

He then divides 30 by 6.32.

He gets about 4.75 foot- layers/sec (value must be rounded to the nearest hundredth since most typical stopwatches do so)

See that was pretty easy..

forget 10 second cars... I want a ten second laser!

#### Meatball

##### New member
What about something other than tape? Paper maybe .. :anyone:
There are SO many varying brands and methods of making black paper. It would be very difficult to control such a variable. That why 3M black tape or Oreos would work better since they are consistently manufactured to a certain standard, and are widely available.

Good thought though!

#### YGG

##### New member
I was just thinking, what if one laser burns through at the same speed as another but burns through the same amound at a further distance when another can't. Maybe the tape layers could be seperated, like every half a foot or something spanning across a certain amount. This way you could measure burning distace as well. Like maybe a green laser burns the same up close as a 405nm but the 405nm has a glass lens and burns better than the green at longer distances.

#### Meatball

##### New member
I was just thinking, what if one laser burns through at the same speed as another but burns through the same amound at a further distance when another can't. Maybe the tape layers could be seperated, like every half a foot or something spanning across a certain amount. This way you could measure burning distace as well. Like maybe a green laser burns the same up close as a 405nm but the 405nm has a glass lens and burns better than the green at longer distances.
Yes I see what you mean. I think though that most lasers capable of burning tape with be able to burn very well at 1 foot. (adjustable focus or not) If a specific distance can't be decided, than we ought to set a limit. Say... focused > foot?

#### lasersbee

##### Well-known member
The other variable is focus... I've heard members complaining that their
100mW Blu-Ray can't pop a balloon... while I have a 50mW Blu-Ray that
burns the wood on clothes pegs...:thinking:

@Meatball... I don't have any other ideas as of yet...

Jerry