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Re: Help!

lasersbee

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Re: Help!

Ignore this Post...
It is a Clipboard to Compose Posts.

####################################

I did a bit of testing on this LPM yesterday....
Here are some results...

It looks like a cute little LPM at first sight.

The first thing I did was look for a USB Charging
cable that was not included with the LPM.
It was drawing just over 500ma... I find that quite
high for the small Li0-Po. I could be wrong.

First I need to mention that about a month ago I
re-calibrated our NewPort LPMs as we do every 6
months or so.

LiPo Charger

The LiPo charger used an off-the-shelf Li-Po Charger
Booster PCB to supply 5Vdc from a 3.7Vdc LiPo
battery. Unfortunately I damaged the Label indicating
the battery capacity when I unstuck it from the White
Silicone.
The PCB is held in place with Hot Snot as Dave Jones
would say.

I drilled a small hole just to the right of the USB
connector which now allows the light from the Charging
and Fully Charged LEDs to be seen while charging.
Unfortunately with the 2nd charge today the Charger
PCB gave up the ghost... I'l need to replace it.
Hope that is not a common problem.

Broadband Coating

I initially tested the LPM using a couple of close-by
Lasers and found that my specific LPM was reading
a little off.

808nm 500mW measured 556mW on 15W LPM... (+11.2%)
650nm 11mW measured 7mW on 15W LPM........ (-57%)
450nm 455mW measured 465mW on 15W LPM... (+2.1%)

By these quick non-in-depth measurements it looks
like the 15W LPM was calibrated at 450nm...
The problem is that the coating does not seem to
be Broadband as shown by the quick test above...

Max Power Test

We use a specific setup when we test our different
LaserBee Thermopile sensor coatings for Max Power.
We use a High Powered water cooled 808nm 40Watt
FAP Laser powered by an adjustable OPC-PS4005 Laser
Power supply.
I used the same Laser Beam Diameter and distance
from the 15W LPM Sensor and proceeded to increase
from 0mW upward.
The Sensor started to smoke at ~4 watts.... The
sensor is definitely not a 15 Watt sensor.

Sensor

Looking closely at the sensor I found it to be a TEC
that measures 10mm X 6mm X 1.5mm with ~50 P/N
junctions outputting ~159mV/W.
The 100% response time was ~21 seconds.

The actual Sensor Plate is a thin copper sheet that
is larger than the Tec and measures ~12.6mm X 11.6mm.
That plate is Paint Brush coated with some type of
black semi-shiny paint.

If a Laser is shone on the Plate over the TEC the readings
will be fine since the TEC will bleed off the heat produced.
If a Laser is shone on the Plate not over the TEC the
heat will build up quickly and reduce the Max power of
the sensor.

It seems that the copper plate is attached to the TEC
by the same white silicone that is liberally used inside the
enclosure. The TEC is mounted to the copper heatsink
again with white silicone.
The finned copper heatsink measures 26.9mm X 16.2mm
X 11.2mm and is also attached to the alluminium enclosure
by again... white silicone.
I can't see this small Heatsink capable of dissipating 15W
even if the Coating could handle it.

Circuitry

I decided to see what kind of circuit was used to
design the 15W LPM. Before receiving it..I was sure it
used the old simple $50 LPM circuit that is freely available
on LPF.
It is however even more simple than that....
Schematic attached below...

There is no Manual or Digital Zeroing control on the circuit
but there is a voltage divider/Calibration pot that directly
feed into an off-the-shelf Voltmeter.

One thing to note.... If you touch the Alluminium case
the heat from your hand will lower the resdings..

Final Thoughts

If you want rough Laser Power measurements in a small
portable enclosure with a re-chargeable Li-Po battery then
this LPM is a fair choice. (Or you could build one since the
circuitry is so simple)


Jerry
 
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lasersbee

Well-known member
Joined
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Messages
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Points
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Re: Help!

Yeah I just noticed he had 2 threads started with the same questions. :-?

Ignore this Post... It is merely a Clipboard for composing
Threads/Posts

Jerry


=[Clipboard #3]=======================================
I do not appreciate the rep you left me Jerry; I have NEVER told a lie to sell my own products.

However, you have lied to sell your products. In more than one instance.

Now since I know you'll make stuff up about me lying if I don't post evidence of you lying to your customers here is evidence of one instance.

Even though I have reported bugs and your own customers have reported bugs:

You've been told by myself, others and your own customers that you have bugs, and you still try to sweep them under the rug to sell your LPM's.
You are a liar Jerry, and you continually demonstrate that in majority of your posts, this thread is another such example.

I have never tried to do any such thing, unlike yourself.

I have always been a big supporter of people making their own LPM's, and sourcing their own parts.
Evidence:
http://laserpointerforums.com/f70/users-thoughts-their-5w-lpm-systems-82197.html#post1181312

I've even made Open Source ARGMeter LPM's for other people to DIY without ANY monetary benefit to me; in fact I lost money on that project. It has always and will always be a fun project for me to work on and doing a service to the community. I've told you before and I will tell you again, I am not here on LPF for monetary benefit exclusively (unlike yourself) I am here to have fun and build all sorts of things, lasers, projectors, LPM's, drivers.

Do you contribute to the community other than spamming your advertisement in the welcome section and trying to get people to buy your LPM's by arguing with every other LPM maker?

I do not appreciate your attack on my word. I am a man of my word. When I said I used a Coherent fieldmax, I used a coherent fieldmax.

Name, date stamp, fieldmax, PM30, Rubicon PCB.

As you can see I am a man of my word.

Now that you are done insulting me, and I am done defending myself let's stick to the science; okay?
Resorting to insults and non-scientific evidence only shows everyone that you don't have any real argument.

Trevor has already said pretty much everything that needed to be brought to your attention, but I will add this.

None of my heads came from LPF members, and there have been ones as high as 7% and as low as 6%. (Tested against the fieldmax)

@Jerry Ophir heads (as per Ophir) should be recalibrated every year for accurate measurements. After sitting in a storage facility for more than a year it would not be unreasonable to expect that a small portion of the heads haven't retained the calibration.
Without knowing the conditions they were stored in we cannot assume they are calibrated perfectly.

Maybe you just haven't had enough Ophir heads to find the few that are uncalibrated?
Maybe where you sourced your Ophir heads from was stored in better conditions than the ones I got?
There are plenty of factors in play here.
:crackup:
Wow... you guys are like a school of Piranhas...
One thinks he smells blood and they automatically all attack...:crackup:

@ ARG...

How can you be surprised that you received a Neg Rep from me...:thinking:
Did you honestly believe that I would ignore you pi$$ing on my boots..:thinking:

Contrary to popular belief this thread is about the lack of a long term
reliable source for more cheap OPHIR heads and the insinuations by
you that the only correctly calibrated OPHIR heads are supplied with
YOUR LPM and not about my company's quite good Customer Service
over the past +30 years.

This is the reason for the Neg Reps from the new
TrevArgometer Posse.:undecided:
Yes.. you now have a new moniker...:eg:




You stated that CLCEN1's Lasers are not Calibrated.

Quite right.

The ones from CCLEN are sold as hardware only, uncalibrated. The ones forum members have sold have been recalibrated, or verified.
I reiterate... All the many OPHIR Heads I had purchaed from CLCEN1 were
within OPHIR's stated +/- 3% accuracy.
I would consider your statement either contrived up or a blatant lie.

Then there was this Quote that you changed recently... luckily I quoted
your passage in my post #80 or you would no doubt accuse me of lying.

I used a NEWER NIST traceable coherent fieldmax to get my numbers. The numerous Ophir heads I have ranged from 6% low to 12% high. All with the original factory calibration.

Most were correct, but not all.
Then you quote this in your last Post...

None of my heads came from LPF members, and there have been ones as high as 7% and as low as 6%. (Tested against the fieldmax)
So which is it when you posted your personal testing info...???
Either it is the former quote and the latter quote was contrived or
a lie or it is the latter quote and the former quote was contrived or
a lie.

Either way you lied about your tests...

In that same quote you state (Tested against the fieldmax).
Ant reasonable person proud of his NEWER Coherent FeildMax TO
would say "tested against MY feildmax".

Why have you blacked out the Item Number and Serial Number
of the Head...
What are you trying to hide and why are you being so deceptive..???
I would think you would be proud to show off a NEW Nist Traceable LPM.



Are you sure that that Coherent FeildMax TO is New and was
purchased by you..???
Sorry to be a doubting Tomas but I'm not convinced...

BTW... I was not insulting you... I'm was just going by what you
post and tried to put some truth to it.

And I was not attacking your word... I was questioning it since
you never showed any proof of your claims.

@Jerry Ophir heads (as per Ophir) should be recalibrated every year for accurate measurements. After sitting in a storage facility for more than a year it would not be unreasonable to expect that a small portion of the heads haven't retained the calibration.
Without knowing the conditions they were stored in we cannot assume they are calibrated perfectly.

Maybe you just haven't had enough Ophir heads to find the few that are uncalibrated?
Maybe where you sourced your Ophir heads from was stored in better conditions than the ones I got?
There are plenty of factors in play here.
All the OPHIR Heads that I received from CLCEN1 were sent in a sealed
Plastic bag. I would assume that no dust would have deposited onto the
Sensor's active surface as witnessed by me under closer examination.

As the Coherent Application Engineer confirmed... If an LPM and/or Sensor
is not used the calibration will not change. It will only change under use.
The heads do not need to be stored in a hermetically sealed box.
Common sense would dictate that just keeping the dust off the Sensor's
surface by keeping them in a sealed plastic bag and not subjecting them
to underwater tests would keep them accurate over time.

I've had quite a few heads pass through the shop in the past 3 years and
the only ones that were uncalibrated came from LPF sellers. I still have the
last three uncalibrated heads fr5om LPF sellers in a cabinet for future reference.

BTW... how many OPHIR 20C heads have you personally tested...


Jerry
 

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