Respectable lux meter that doesn't cost $4k - Page 1
Forum section: electronics / testgear

author: s_lannan
author_rank: Contributor
timestamp: November 24, 2014, 11:02:29 am
content: Any ideas? Something of decent pedigree however....

author: mcinque
author_rank: Unknown
timestamp: November 24, 2014, 12:43:41 pm
content: maybe a sekonic could do the job? It's a pretty respectable brand.http://www.sekonic.com/products/i-346/overview.aspxAbout € 190

author: saturation
author_rank: Super Contributor
timestamp: November 25, 2014, 01:27:51 pm
content: For what purpose?https://www.eevblog.com/forum/buysellwanted/recommendation-neeed-lux-meter/msg492741/#msg492741Professionally any luxmeter with a valid traceable calibration certificate can be used, and the spectral validity with be on the certificate.

author: Fungus
author_rank: Super Contributor
timestamp: November 25, 2014, 02:23:23 pm
content: While we're at it, any recommendations for a cheap one?Ballpark values, +/-10% would be fine (although 5% would be better). How accurate are these things anyway?

author: saturation
author_rank: Super Contributor
timestamp: November 25, 2014, 02:53:59 pm
content: The accuracy depends on cost, price rises with accuracy < = 1% and/or much finer resolution in lux [0.1 lux or better]. Any meter that is calibration grade will be commercial grade even if you don't get a certificate.For example, USA buyers for use in working and living conditions lighting evaluation:http://www.pro-measure.com/product_p/lm-81lx.htm$80.With cal certificate, ~ 2x the cost:http://www.pro-measure.com/category_s/30.htm

author: eliocor
author_rank: Unknown
timestamp: November 25, 2014, 06:35:32 pm
content: ISO9002 is NOT a certificate of calibration...

author: saturation
author_rank: Super Contributor
timestamp: November 25, 2014, 09:31:47 pm
content: For lux requirements in homes and workplaces, a meter of <= 20,000 lux or ~ 2,000 fc is more than adequate. Even a resolution as low as 10 lux works, that's ~ 1 fc. Most commercial meters can resolve 1 lux to accuracy better than 10%, as that $80 device. Yes, the chassis can be cheap, but it gets the job done.US OSHA:https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10630Some other recommended values:http://www.bosworthinstrument.com/Lightmeterinfo.html

author: Mr.B
author_rank: Unknown
timestamp: November 25, 2014, 09:50:15 pm
content: Quote from: Fungus on November 25, 2014, 02:23:23 pmIf you want a really ballpark figure and you have an Android phone there are free apps available.Really, really ballpark though...

author: Monkeh
author_rank: Super Contributor
timestamp: November 25, 2014, 09:58:42 pm
content: Quote from: 3roomlab on November 25, 2014, 03:23:27 pm

author: Fungus
author_rank: Super Contributor
timestamp: November 26, 2014, 02:03:00 pm
content: Quote from: Mr.B on November 25, 2014, 09:50:15 pmI never thought of that.Looks like there's quite a few apps available and they use the front-facing camera to measure light. I imagine they're not very accurate but the price is right.

author: DanielS
author_rank: Frequent Contributor
timestamp: November 26, 2014, 04:48:17 pm
content: Quote from: Fungus on November 26, 2014, 02:03:00 pmThey do not use the camera; they use the ambient light sensor used to manage automatic screen brightness.

author: s_lannan
author_rank: Contributor
timestamp: December 02, 2014, 12:24:35 pm
content: Thanks for all the replies...I wanted something that would verify a lumen output spec with a little accuracy... maybe less than $1000 worth of kit.To elaborate our local supplier "Jaycar Electronics" has this nasty habit of promoting the standard shenzhen crap as "the ducks guts"......

author: Gall
author_rank: Frequent Contributor
timestamp: December 02, 2014, 06:03:54 pm
content: What exactly do you want to measure? What accuracy do you need?In many cases just a photodiode or something like OPT101P is adequate. There are many methods of DIY calibration that are reasonably accurate.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 04, 2014, 01:16:02 pm
content: I have theBEHA UNITEST 93560 Luxmeter digitalGot it for a super deal on ebayRetail is around Euro 150

author: HighVoltage
author_rank: Super Contributor
timestamp: December 09, 2014, 01:53:08 pm
content: What TES model do you have?I saw some with a sensor that looks that same but thye base unit looks a little different.Here are 2 pictures on my Beha Lux Meter