Improvised power meter for the rest of us...

Benm said:

I'd say, settle for DIY and limited accuracy then. 10% might sound pretty bad, but its still valuable to see if a laser you bought is at least near spec, and it will also clearly show any improvement in homebuilt lasers you obtain by increasing current, using better lenses and such.

Click to expand...

What do you have in mind? Same one i do (those ref and input diodes), or something else? I'm open for all ideas (that do not cost xx.xxx $$$)
:can: lookin' for ideas.

bobhaha said:

Isn't the laser check like $900?? (IIRC ) I dont think thats in his price range!

Click to expand...

The Coherent LaserCheck is +/- 5% accurate and cost between $350.00 US
to $500.00 US new dependimg on where you buy it and the shipping costs..
Ours cost us $520.00 Cnd by the time we had it in the shop...

It also has an issue getting accurate/consistant readings with 405nm LDs..

BTW.. for a DIY inexpensive LPM... 10% accuracy is quite acceptable and
is pretty good... IMO

@Silvershot...

It would be nice if some1 came up with an idea which would lead to a "cheap" working LPM.

Click to expand...

How can you ask such a question after all the time you have been here...:undecided:
Don't you even read the Posts on the Threads you post on...:thinking:
Read post #9 of this Thread and follow the instructions for the Link provided...
Those are all the LPF DIY LPM Projects all in one area so you don't even need
to do any research....
I couldn't make it any easier....:evil:

Jerry

lasersbee said:

The Coherent LaserCheck is +/- 5% accurate and cost between $350.00 US
to $500.00 US new dependimg on where you buy it and the shipping costs..
Ours cost us $520.00 Cnd by the time we had it in the shop...

It also has an issue getting accurate/consistant readings with 405nm LDs..

BTW.. for a DIY inexpensive LPM... 10% accuracy is quite acceptable and
is pretty good... IMO


Jerry

Click to expand...

Sure, as long as you build it
You have any particular idea in mind?

The one Benm was referring to.. using the diodes... is his design...
Another LPM that looked promising was the IR Thermometer one...

If you don't want to spend money... no-one will buy the parts and
build it for FREE for you...

"No money... no candy"... I think Santa got hit by the recession
and is on strike...:crackup::crackup:

You could stick a wet finger into the air to find the "exact" wind speed
and "exact" direction... or you can build or buy the required Equipment...

One is FREE and the other cost some funds....



Jerry

HAHA when i said "as long as you build it" i didn't mean particulary you, i meant, you know, it is good as long as 'one' has it.

Ofcourse i know nobody is going to bould it for free, and i don't want nobody to build it for free, where is the fun for that?

Before you try ANY of these cheap/expensive DIY methods, you need to see if your school's lab has a meter to calibrate your own to. All these heat sensors--thermistors, thermometers, thermopiles, photodiodes, whatever--are not made the same, and therefore need calibration to a known source.

Some people have tried calibrating using a power resistor and black body radiation, but that is, again, assuming your have a perfectly black surface for converting light into heat, which you will not. So you even need to calibrate the absorption surface for that.

Perhaps you could build something and send it off to have someone calibrate/give you values for it.

That is great idea. However I 'm still away quite a bit from building it

Let's pin that idea and take it when i have something.
By someone you mean you?

lasersbee said:

@Silvershot...


How can you ask such a question after all the time you have been here...:undecided:
Don't you even read the Posts on the Threads you post on...:thinking:
Read post #9 of this Thread and follow the instructions for the Link provided...
Those are all the LPF DIY LPM Projects all in one area so you don't even need
to do any research....
I couldn't make it any easier....:evil:

Jerry

Click to expand...

Guess I am a bit lazy reading I 'll be more careful from now on!