DIY Laser Power Meter Projects...

[lasersbee]

^^^^ I've seen this foot fetish post before.....:crackup:

Same questions I posed there still apply...

http://laserpointerforums.com/f44/im-getting-error-message-my-laser-bee-73879.html#post1070166


Jerry

You can contact us at any time on our Website: J.BAUER Electronics

 

[Seoul_lasers]

Hey, I recognize this wiring diagram!! :wave:

WOW!! Good to hear that the wallwarts worked! I was a little hesitant because of the possibility they may be noisy or cause interference. If you aren't having this issue then that's good! I was under the impression Ophir heads need a very "quiet" PSU to be accurate.
Great pics! Now you'll need to find a way converting your raw signal to match the true output . currently is showing 333mV:1000mW. (opamp possibly or perhaps do a "Trevor" and build a full out lPM using an Arduino or Maple?)

 

[lasersbee]

Hey, I recognize this wiring diagram!! :wave:

WOW!! Good to hear that the wallwarts worked! I was a little hesitant because of the possibility they may be noisy or cause interference. If you aren't having this issue then that's good! I was under the impression Ophir heads need a very "quiet" PSU to be accurate.
Great pics! Now you'll need to find a way converting your raw signal to match the true output . currently is showing 333mV:1000mW. (opamp possibly or perhaps do a "Trevor" and build a full out lPM using an Arduino or Maple?)

I feel you are assuming that ratio....

That ratio you state would depend on the exact original OPHIR
calibration....

It was stated as 0.3V/Watt... which would be 300mV/1000mW
Just like a calibration of 0.1V/Watt is 100mV/1000mW.


Jerry

You can contact us at any time on our Website: J.BAUER Electronics

 

[Machinist Joe]

Wow! This is cool!

Where is the best place to buy one of these heads?

EDIT: Cheapest one I found is $200

 

[Trevor]

Great thread! Does somebody has the circuit of MarioMasters lpm? I can't find it

Drop MarioMaster a PM. I've no idea why it isn't in this thread.

Wow! This is cool!

Where is the best place to buy one of these heads?

EDIT: Cheapest one I found is $200

Yeah, they're not cheap. They were surplus for ~$50 a couple years ago, but the price has been steady at ~$200 ever since.

Trevor

 

[tsteele93]

Here is the MarioMaster Schematic for the $50 low cost DIY LPM... (laser power meter)

Also, I'll put this here as well in case it helps someone trying to wire up a power supply to the Ophir head:


Ophir LPM Schematic by tsteele93, on Flickr

 

[Seoul_lasers]

I feel you are assuming that ratio....

That ratio you state would depend on the exact original OPHIR
calibration....

It was stated as 0.3V/Watt... which would be 300mV/1000mW
Just like a calibration of 0.1V/Watt is 100mV/1000mW.


Jerry

yes, sure was. Ok, 300mV/1000mW .3V/1W.. was confused.

 

[Machinist Joe]

I might have to pick an Ophir up tomorrow. Sucks they are so pricey!

@trevor
I am planning to build one with an arduino, but I just ordered my first one, and am just starting to learn. Would it be possible for some help with this sooner or later? You seem like the man when it comes to this stuff! :wave:

Thanks.

 

[Seoul_lasers]

I might have to pick an Ophir up tomorrow. Sucks they are so pricey!

@trevor
I am planning to build one with an arduino, but I just ordered my first one, and am just starting to learn. Would it be possible for some help with this sooner or later? You seem like the man when it comes to this stuff! :wave:

Thanks.

They are pricy for a good reason. Their response time is about 1.5 seconds. Just about instant reading, and they are pretty much dead accurate to boot.

 

[Machinist Joe]

I know I want one so badly. Lol

Worth the $200, but I know I'm going to over engineer the crap out of it. I'm considering adding a touchscreen display with Power graphs. Why you may ask? I have no idea... Because I can. :tinfoil:

I get my paycheck tomorrow and I know what I'm going to blow all my money on...

They are pricy for a good reason. Their response time is about 1.5 seconds. Just about instant reading, and they are pretty much dead accurate to boot.

 

[lasersbee]

They are pricy for a good reason. Their response time is about 1.5 seconds. Just about instant reading, and they are pretty much dead accurate to boot.

Only if your laser's beam is accurately dead center and any
surplus or 2nd hand OPHIR Head is verified to be accurately
calibrated...

We have seen "new surplus" OPHIR 20C heads off by ~9%-10%
on the Forum.
I wouldn't assume an OPHIR head was accurate unless it came
directly from OPHIR and recently calibrated or was recently
calibrated against a known accurate LPM.


Jerry

You can contact us at any time on our Website: J.BAUER Electronics

 

[Seoul_lasers]

Only if your laser's beam is accurately dead center and any
surplus or 2nd hand OPHIR Head is verified to be accurately
calibrated...

We have seen "new surplus" OPHIR 20C heads off by ~9%-10%
on the Forum.
I wouldn't assume an OPHIR head was accurate unless it came
directly from OPHIR and recently calibrated or was recently
calibrated against a known accurate LPM.


Jerry

You'd be right in assuming , I am assuming it has been properly calibrated, that is unless the Ophir sensor has been "tampered with"... :wave:

I thought they were as much as 3% out maximum... hmmm.... Didn't know they'd be up to 10% off.
Would that not mean the sensors would start reading abnormally high from background heat?
These are industrial sensors and their response time is incredible.

 

[tsteele93]

Only if your laser's beam is accurately dead center and any surplus or 2nd hand OPHIR Head is verified to be accurately calibrated...

We have seen "new surplus" OPHIR 20C heads off by ~9%-10% on the Forum. I wouldn't assume an OPHIR head was accurate unless it came directly from OPHIR and recently calibrated or was recently calibrated against a known accurate LPM.


Jerry

Mine was still sealed in the factory packaging and it looks like it is dead on! I also got it for a good price, the seller accepted a "make offer" price that was nice and he shipped free and included the two 12v/1A wall warts that I ended up using. So I got a good deal I think.

I did move it around a little while getting the beam centered and I wasn't seeing very much difference from center to outer edges. I think only 3-5mW, I'll try to watch for that and see next time.

I'm glad I have both. The Laser Bee A is easy to use and works well, the Ophir is a bit messier as it is wired up right now and you need a GOOD DMM to use it well. So if you don't already have one then it is an extra expense. I do like the instant readings and the ability to measure very high wattage if the need arises.

Like everything, there are tradeoffs.

 

[Seoul_lasers]

Mine was still sealed in the factory packaging and it looks like it is dead on! I also got it for a good price, the seller accepted a "make offer" price that was nice and he shipped free and included the two 12v/1A wall warts that I ended up using. So I got a good deal I think.

I did move it around a little while getting the beam centered and I wasn't seeing very much difference from center to outer edges. I think only 3-5mW, I'll try to watch for that and see next time.

I'm glad I have both. The Laser Bee A is easy to use and works well, the Ophir is a bit messier as it is wired up right now and you need a GOOD DMM to use it well. So if you don't already have one then it is an extra expense. I do like the instant readings and the ability to measure very high wattage if the need arises.

Like everything, there are tradeoffs.

Yes and I'll agree about the DMM accuracy too. You need a DMM like a FLUKE or HIOKI that has high accuracy and high resolution to get decent measurements.
no offense to Jerry, the laserbeeA,I and II is accurate, but they cannot see the peak energy due to their high response time. They ARE good at showing after peak energy.
Laserbee 5W is attractive for quick response time/peak energy purposes.

 

[Trevor]

Only if your laser's beam is accurately dead center and any
surplus or 2nd hand OPHIR Head is verified to be accurately
calibrated...

We have seen "new surplus" OPHIR 20C heads off by ~9%-10%
on the Forum.
I wouldn't assume an OPHIR head was accurate unless it came
directly from OPHIR and recently calibrated or was recently
calibrated against a known accurate LPM.


Jerry

I assume you're referring to my findings, which were flawed due to reference laser not outputting what its onboard diagnostic said it was.

We have not yet seen any systematic inaccuracy among the surplus Ophir sensors. If you have numbers to back up your assertion, I'm all ears.

I'll give you the benefit of the doubt and assume that you have data, and are not trying to discredit Ophir sensors for the sake of selling more LaserBees.

I'm awaiting your data.

Trevor

 

[lasersbee]

I assume you're referring to my findings, which were flawed due to reference laser not outputting what its onboard diagnostic said it was.

We have not yet seen any systematic inaccuracy among the surplus Ophir sensors. If you have numbers to back up your assertion, I'm all ears.

I'll give you the benefit of the doubt and assume that you have data, and are not trying to discredit Ophir sensors for the sake of selling more LaserBees.

I'm awaiting your data.

Trevor

Troll fail....:cryyy:

No... I'm referring to all findings on the Forum including our own
in shop tests of these OPHIR 20C Heads...

I'm definitely not discrediting a well known companies products..
What I am saying is that we have seen on the Forum and in our
shop, OPHIR surplus sensors off eBay that were up to ~10% off
calibration.
I'm just saying... don't believe that the OPHIR sensor that you
may get is 100% accurate without verifying it.

You are very aware of this since you even tested that head for
that other member that found discrepancies between his LaserBee
2.5W USB and his OPHIR head...
It was later found that the problem was the OPHIR head reading
~9%-10% too high and was reported on the Forum..

Since you referred to the heads that you had reported on and recently
sold.... I know that you corrected your 1st post data to show that your
initial readings were OFF due to your brand new Coherent Cube Laser
being off by ~9%....:thinking:

But the fact remains that at least one your heads was still off by ~5%.

I hope that data sums it up for you....

BTW I didn't link to all the Threads and Posts I made mention to...
I'm sure you know where they are... :beer:


Jerry

You can contact us at any time on our Website: J.BAUER Electronics