What kind of light meter should I get?

[PaulW]

As my collection grows I find that "measuring" light levels by comparing two flashlight beams is tedious and inaccurate. I want to do that better and I want to be able to measure beam patterns and do run-time tests.

Ideally, I would like an industrial lux meter with 1% accuracy, but that's hundreds of dollars. Even a 4% lux meter costs $55 on eBay. And it looks like the old-fashioned used exposure meters (that give only indications of relative levels) on eBay selling for $10 to $20 are accurate to, at best, 20%.

I haven't gone down to radio shack, but when I do, I don't expect much. Their web site and its search function have not been helpful.

What do you use? Where did you get it? Any tips for me?

What would you do? Try to make a cheapie work? Bite the bullet and get the good ($55) one?

I can't ask my friends for advice on this. This would only confirm their suspicions that I have become a little weird about flashlights.

 

[Roy]

Look at these:

http://www.testequipmentdepot.com/extech/lightmeters/index.htm

 

[Slick]

The wavetek/meterman LM631 is what many members on CPF use (me included).

 

[Sigman]

Take a look at this thread... There was a lot of discussion in the "Electronics Forum. Batteries Included" Forum of the CPF. Search there for newer than 1 year, using Lux, Lightman, Wavetek, Lightmeter...I think you'll find several posts.

 

[PaulW]

Yes, yes, yes. I have been following the helpful advice each of you has given. Thanks.

I've looked at a lot of pages, and so far the Wavetek Meterman LM 631 is looking very good to me. If I do finally decide on this meter, then my search will be for the best price. (I'm collecting such data already. I notice from old posts that Circuit Specialists recently had a sale on the LM 631. Perhaps I could give them a call and see what I could talk them into.)

But, for now, still searching & studying . . . .

 

[Sigman]

Paul, email sent...to your loooooong email address! /ubbthreads/images/graemlins/grin.gif

 

[ufokillerz]

circuit specialist never got back to me about my possibly defective wavetek meterman631 after quite sometime, i think about a month by now.

 

[FalconFX]

Have you called them up about it?

I just ordered my Meterman from CC and it's scheduled to arrive tomorrow...

 

[PaulW]

Sigman - I really appreciate the suggestion in your e-mail and for taking the time to send it. I'm getting closer to making a decision.

FalconFX - I haven't called CC yet. I generally like to wait on decisions like this for a peiod of 24 hours. But I am leaning heavily in this direction.

ufokillerz - Thanks for the warning. This is entering into my decision. But tell me, what seems to be the problem with the 631? You say "possibly defective." The word "possibly" intrigues me.

 

[ufokillerz]

[ QUOTE ]
Slick said:
[ QUOTE ]
ufokillerz said:
i recently got a LM631 also and from the conditions i described to meterman, they tell me that mines defective, i can't seem to register much with a the peak max on. I have a light that can and will hit 2000 lux and over, but in x10 mode with peak max on, it wont budge.. meter is always stuck at ~142 in x10 mode. Anyone have any clue at whats going on, and what you get when you hit peakmax.

[/ QUOTE ]

I too have a LM631 light meter, and am also having problems using the "peak hold" feature. The meter seems to work just fine if I don't use the peak hold feature. If I turn on peak hold (even with the cap over the photo sensor) the meter will jump up 117 units (of measurement) depending on what range it's set for...

I have a open call into Wavetek on this problem but have not received a response yet. Since this problem seems to be somewhat "widespread", I will post a discussion topic in it's own thread when I find out what's going on.

[/ QUOTE ]

its been a while, never had the time to call, so probably too late now anyway, i was hoping for a tech on their side to possibly tell me whats wrong, i will probably send the meter back to wavetek/meterman when i feel i need the peak hold function.

 

[Blikbok]

Crap, I was looking at the LM631, and I was looking to use the peak hold a lot. /ubbthreads/images/graemlins/frown.gif Does anyone have the LM631, and *not* have a problem with the peak hold?

 

[ufokillerz]

plenty of people have no problems with it, not everyone has problems

 

[Slick]

[ QUOTE ]
ufokillerz said:
[ QUOTE ]
Slick said:
[ QUOTE ]
ufokillerz said:
i recently got a LM631 also and from the conditions i described to meterman, they tell me that mines defective, i can't seem to register much with a the peak max on. I have a light that can and will hit 2000 lux and over, but in x10 mode with peak max on, it wont budge.. meter is always stuck at ~142 in x10 mode. Anyone have any clue at whats going on, and what you get when you hit peakmax.

[/ QUOTE ]

I too have a LM631 light meter, and am also having problems using the "peak hold" feature. The meter seems to work just fine if I don't use the peak hold feature. If I turn on peak hold (even with the cap over the photo sensor) the meter will jump up 117 units (of measurement) depending on what range it's set for...

I have a open call into Wavetek on this problem but have not received a response yet. Since this problem seems to be somewhat "widespread", I will post a discussion topic in it's own thread when I find out what's going on.

[/ QUOTE ]

its been a while, never had the time to call, so probably too late now anyway, i was hoping for a tech on their side to possibly tell me whats wrong, i will probably send the meter back to wavetek/meterman when i feel i need the peak hold function.

[/ QUOTE ]

ufokillerz - Call Wavetek at 1-877-596-2680 and ask for Jim Newell. I have been too busy with other things to pursue what's going on with the peak hold feature.. Let us know if you find out anything new, thanks.

 

[PaulW]

Should I worry if there is a chance that a LM 631 that I would buy would have a peak hold problem?

I cannot think of any use I would have for this feature, so I see no reason why that should deter me from getting the meter. I am guessing that peak hold is useful only for illumination engineers in the presence of light intensity fluctuations.

But am I missing something? Might I eventually want to use the peak hold feature? What do YOU use it for?

 

[FalconFX]

The peak hold shouldn't deter you from buying the Meterman. The only reason I see peak hold as a viable option is when I need to take a picture of it. And even at that, I can still take a snapshot without peak hold...

 

[The_LED_Museum]

My meterman does that too - the reading continues to climb up if the peak hold button is used, even if the black lens cap is still on. But I just use my own eyes and memory to get the peak reading, so it's not of major concern to me.

 

[Slick]

[ QUOTE ]
The LED Museum said:
My meterman does that too - the reading continues to climb up if the peak hold button is used, even if the black lens cap is still on. But I just use my own eyes and memory to get the peak reading, so it's not of major concern to me.

[/ QUOTE ]

This is EXACTLY what mine does too... I suggest that you call Wavetek and speak to Jim at the # I posted above...

That being said, I still think it a great meter because everything else on it works great - which is why I'd still recommend one.

 

[Sigman]

Mine does not do that. The peak reading holds, I use it all the time to get the "hottest reading" from whatever part of the beam is the "hottest"...I move the torch around as I'm aiming it at the sensor...I find the hottest spot and it ceases climbing.

You aren't holding down the peak hold button are you? I just click it once...hmmmm...

 

[PaulW]

Well, I did it.

I ordered the Wavetek Meterman LM 631 light meter -- $92.39 incl. shipping and with the DMM bonus -- from Circuit Specialists.

Thanks to everyone for your information, advice, suggestions, and warnings. They helped a great deal.

 

[Blikbok]

I'm gonna make the jump and buy the multimeter/light meter. This forum is turning me into an EE. I'm not sure that's good yet.