Options for laser power meters

[Don Corbeil]

I was about ready to go with an analog, but then found a nice used Macken DM5 (with new probe!) on ebay for $150.
With the detachable probe on a flexible cord, it should be easy enough to place it, even in hard to get to spots.
macken.jpg

[Keith Winter]

I was about ready to go with an analog, but then found a nice used Macken DM5 (with new probe!) on ebay for $150.
With the detachable probe on a flexible cord, it should be easy enough to place it, even in hard to get to spots.
macken.jpg

Sounds like a steal don! Nice find!

[Dave Sheldrake]

What I do know is that it is consistent

Sadly consistently bad in most cases as are most thermal calorimeters when it comes to laser beam measurement. About all they are good for is an idea of change rather than accurate readings as a number of factors that affect laser power are ignored in such a test.Up against my lab rig they can be anything up to 30+% out

[Don Corbeil]

Sadly consistently bad in most cases as are most thermal calorimeters when it comes to laser beam measurement. About all they are good for is an idea of change rather than accurate readings as a number of factors that affect laser power are ignored in such a test.Up against my lab rig they can be anything up to 30+% out

Sadly, most of us also don't have access to a lab, Dave!
So we have to make do

[Dave Sheldrake]

Sadly, most of us also don't have access to a lab, Dave!
So we have to make do

was more intended to show how inaccurate they can be ( I mean the cooking thermometer versions with a block of ally on the end)

A good way to make your own is google Dr Lindsay Wilson as he has a full run down on making one for about 5 bucks (and is an all round clever chap)

[Don Corbeil]

was more intended to show how inaccurate they can be ( I mean the cooking thermometer versions with a block of ally on the end)

A good way to make your own is google Dr Lindsay Wilson as he has a full run down on making one for about 5 bucks (and is an all round clever chap)

Dave,

Aren't the digital type (ie synrad PW250, macken DM5) also thermal calorimeter types, ie measuring changes in temperature?

[Dave Sheldrake]

Dave,

Aren't the digital type (ie synrad PW250, macken DM5) also thermal calorimeter types, ie measuring changes in temperature?

yup many are Don but they are made to NPL Traceable standards rather than a well intentioned bodger with some super glue and a $3 ebay cooking thermo the macken and power wizzard are excellent and will 99% of the time hit within 10th's of a watt at worst and often better than that even. For all practical intent and purpose the Mac and the PW are lab standard

What causes me the most concerns are the home made and cheaply made chunks of aluminium glued onto stainless cooking thermo's that are then used to phone the suppliers with complaints of "My $10,000 80 watt machine is only putting out 70 watts according to my $5 meter"

[Don Corbeil]

Thanks for clarifying. I'm relieved

[Scott Cowell]

Don,

I am nearing the purchase of my first laser and have been doing quite a bit of "research" which, of course, includes watching "Tool-Porn" on YouTube. If you lookup:RDWorks Learning Lab 53 Power Meters and the doHICky comparator



you will find a retired gentleman in the UK who shares his adventures in learning about his Cinese E-bay laser engraver. His Youtube account is SarBarMultimedia. In this particular episode he explains power meters, checking his machine, and how he built his own meter. I believe he was even selling the tough to build bits directly. I find him interesting, entertaining, educational and inspirational. If and when I decide to purchase a power meter I will certainly look him up. I would rather send my hard earned cash to a fellow hobbyist rather than a mega-corp. - I have no problems with mega-corps, but you just gotta support the little guy who lets you look over his shoulder, ask silly questions and who shares his successes as well as his follies. After all, isn't that why we do forums? To help each other? - Enough soap box; more cheerleading: Check out his channel, have fun, and let us know what you end up with and how happy you are with your decision.

Scott.

[Don Corbeil]

Scott, welcome to the forum!
I haven't yet looked up your given source, but for me, I want the tool the works best for the job whether it be a corporation or a hobbyist that produces it. That said, I had already made a choice (see above) going with a used macken DM5. I will however look for the video you are mentioning. Good luck in your laser search.

[Bill George]

I looked at the one on eBay also, and its rather vague in the description about the power level its intended for and the Product description on the their website lacks any user documentation? I would be gun shy on this item.

[Don Corbeil]

Bill, I'm not certain which one you are referring to, but the one I ordered is coming over from Cork, Ireland. It was only after quite a few emails between me, the seller, and a Macken technician that I was sure I knew what I was getting. I am always very careful on ebay

[Bill George]

I emailed the seller and got a very confusing answer about what attachment comes with the meter. They claim 5% accuracy the list of attachments for sale with the meter had no power or other details... just a bunch of part numbers and they don't cross over to anything on the website.

[Ian Johnson]

I picked up one of the Ebay ones anyway. Looking at the description of the sensors on the Macken site, it appears to be the smallest one, meant for 20-220W which covers my 60w C02.

[Greg Holt]

Sadly consistently bad in most cases as are most thermal calorimeters when it comes to laser beam measurement.
About all they are good for is an idea of change rather than accurate readings.........................

That was my point. Consistency is all I hoped for from it.

As I said I am not sorry I bought it.