CIE图可视化: https://company235.com/tools/colour/cie.html https://www.luxalight.eu/en/cie-convertor

UVI测试仪到底该朝向哪个方向测试?灯的正中心?最大值点?积分?

上一章节

《光照与加热》

光照的测试

Solarmeter 6.5其实一直到UVA1都有响应

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Bahakiya Yamamoto Thomas Griffiths Hi Thomas, if you put the case back together will it still be accurate? What if it's used without the case? (i.e., Does it have a light-proof seal between the filter and the light sensor, or does it rely on the dark environment created by the case?) I kinda want to create a data recording device, so I can put together an auto-isoirradiance chart plot machine by adapting it to my obsolete 3D printer. But I haven't gathered the courage to mess with my meter.

Thomas Griffiths
Moderator
Bahakiya Yamamoto this one is not very accurate, no.
We’ve seen some that have been taken apart and then reassembled with an adjustable case that seem to be fairly accurate still!
You can see them and their results in the big comparison document: https://tomaskas.co.uk/.../5.30.4.2023-Radiometer-Test...
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Bahakiya Yamamoto
Thomas Griffiths That's a great dataset! I'm surprised that the 3D printed case give systematically lower UVI compared to other meters. I would presume the PLA print would leak more light than a properly made light-proof case.

Sarina Wunderlich
Bahakiya Yamamoto wonderful idea to have an automated isoirradiance device. I have tried once with recording the display with a camera, because I also did not want to mess with the meter for fear of destroying it. See: https://www.licht-im-terrarium.de/mess/irradiance_setup
The first prototype was working (you see it in the video), but there were still a lot of things unfinished and I found no time to continue.
As long as you are not testing metal halide or mercury vapour lamp you can point the lamp to shine sidewards, so that you can also have your meter in a horizontal plane. That makes life much easier und you might not even need the full capacity of a 3D-printer frame to move the meter. This would increase the area that you can cover. If I had time to start again, I would do that. Place the meter on a rotation plate and this on a xy-table.
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Sarina Wunderlich
Bahakiya Yamamoto
> 'm surprised that the 3D printed case give systematically lower UVI compared to other meters.
You see in the photo, that the sensor is directly connected to the board. The electrical current generated by the sensor after the very strict spectral filter is tiny, so the connection needs to be as short and direct as possible. In the 3D printed case where the sensor could be rotated, the sensor had to be disconnected from the board. The wire used to re-connect it most likely has a higher resistance and thus the lower reading.
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Batrakov Sergey
Author
Sarina Wunderlich You mean measure each source using SolarMeter and take its values as reference.
And then buy some kind of sensor, for example even VEML6075.
And is it easy to program/fix on the VEML6075 sensor via multipliers in the ESPHome configuration?
https://esphome.io/components/sensor/index.html
Sensor Component
ESPHOME.IO
Sensor Component
Sensor Component
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Bahakiya Yamamoto
Sarina Wunderlich Thank you Sarina! It's great to see you've advanced further than me. Your plan aligns closely with mine. I plan to position the meter at the intersection of two rods, moved by stepper motors in a CoreXY setup (https://www.youtube.com/watch?v=_ramiM3KHYE&t=6m45s). The meter and lamp is raised away from the platform to avoid table reflections.
It is driven by Marlin firmware and controlled by G-code files.
About the "rotation plate" on the XY-table – is it to aim the meter at the lamp's center? I plan to 3D-print a meter holder with a bearing, allowing it to freely rotate on the x-y axis. A fishing line will be tied to the holder, running through a pulley whell near the lamp's center (on the back of the fixture), then to a weight to keep it tight. This way, the meter should passively point to the center without needing another motor.
Please share if you see some problems with my plan.
CoreXY explained: Comparison + strengths & weaknesses
YOUTUBE.COM
CoreXY explained: Comparison + strengths & weaknesses
CoreXY explained: Comparison + strengths & weaknesses
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Sarina Wunderlich
Bahakiya Yamamoto
The CoreXY setup looks nice.
> This way, the meter should passively point to the center without needing another motor.
I like the idea of making it passive. But it limits you to testing point-like lamps. It will not work for fluorescent lamps or bar-shape LED lamps.
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Bahakiya Yamamoto
Sarina Wunderlich This got me thinking. I see the canonical way is to take the maximum UVI value. However, does this really represent what the animal gets when we use a non-point source? Shouldn't we do some sort of integration/average?
I give two extreme examples. It's not practical, but it shows the conceptual difference:
1. Suppose we have two point-source lamp pointing to a patch of ground in the middle. When we put the meter in the middle. We get two maxima when we point to each lamp, each with UVI = X. What the animal gets would be the sum of the two sources, or effectively UVI = 2X.
2. Suppose we have a point source with certain UVI when we point directly at the lamp. Now we make some half-circle floresent tube, all shining towards the center, such that we get the same UVI in all 180 degrees. The animal will receive much more UV in the latter case. But this difference isn't shown in the "find maximum UVI" method.
Obviously the meter isn't perfectly directional as the meter has a diffuser. But as long as the meter cares more about what's directly in front of the meter, this problem persists.
20h


Sarina Wunderlich
Bahakiya Yamamoto
Very good question. I know that I discussed this with Frances in the beginning as well. I think it would be both valid to take the highest reading by pointing the meter towards the lamp and taking the reading on a horizontal plane with the meter pointing directly upwards / vertically. It's a matter of taste, but we should be consistent, and so as Frances started pointing the meter towards the direction of the highest reading, I and also Thomas sticked to that. But I would also love to hear your thoughts, Thomas and Frances.
> Obviously the meter isn't perfectly directional as the meter has a diffuser.
It is good that the meter has a diffusor! Many meters lack a diffusor and that is bad, because it is not representing the reality. Often in cheaper meters the sensor is sealed below a protective glass some millimeters below the edge of the housing. Thus light coming from the side does not reach the sensor and is not contributing to the reading. But it should contribute. Because skin does not care from what direction the light comes as long as it is reaching it's surface. Of course as the area covered by a light beam becomes larger whan the light beam comes from an angle, the intensity decreases. This is also calles "cosine law" and thus the diffusor is often called "cosine corrector". I have tested the cosine response of a Solarmeter and found it quite good.
https://www.licht-im-terrarium.de/.../uv-index_meter... (see photo - the Solarmeter is reading only slightly too high for 0° and slightly too low for 45° upwards).
> However, does this really represent what the animal gets when we use a non-point source?
So yes, just because the Solarmeter has a good cosine corrector it predicts what an animal gets. And also the animals orient themselves towards the lamp. Having a "flat" bearded dragon under the lamp is not the only way a lamp is used. I sometimes used a focussed metal halide lamp with my daygeckos with no basking branch directly under the lamp but a vertical branch slightly off center, so the geckos were basking in vertical position sideways to the lamp. The were getting more UVI than I would measure with Solarmeter at that position pointing vertically. So I do think pointing the meter towards the highest reading is somewhat correct.
> 1. Suppose we have two point-source lamp pointing to a patch of ground in the middle. When we put the meter in the middle. We get two maxima when we point to each lamp, each with UVI = X. What the animal gets would be the sum of the two sources, or effectively UVI = 2X.
You are correct here. That is a con for the "maximum reading" method. If you use the "vertical meter" method you could simply add the numbers of two spread charts. With the "maximum reading" method you have to re-do your whole measurement with two lamps. I have once done this for Reptiles Expert MH lamps, and just found out that I have not added the graph to the respective report. I should do that later.: https://www.licht-im-terrarium.de/.../lamptestreport...
> 2. Suppose we have a point source with certain UVI when we point directly at the lamp. Now we make some half-circle floresent tube, all shining towards the center, such that we get the same UVI in all 180 degrees. The animal will receive much more UV in the latter case. But this difference isn't shown in the "find maximum UVI" method.
A tiny flat reptile will get exactly the same UVI - because of the cosine correction of the meter. I guess a convex reptile will get a higher UVI from the "rainbow arc" like fluorescent tube, because there it's skin is more often perpendicular towards the lamp. But calculating it exactly might result in a surprise, I am not completely sure.
Summarizing: I think both methods, (a) poiting the meter towards the maximum reading and (b) pointing the meter straight upwards have their pros and cons. None of them fully represent the availible UVI in each kind of sitiaiton (size and orientation of the reptile). But I do not think we will make a big error with either of the methods. For consistency I chose to stick to Frances' method.


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Hello. Has anyone compared XAR-U06 with Solarmeter?

https://www.amazon.com/Ultraviolet-Display-Radiation-Intensity-240-320nm/dp/B0C4DP4H4S

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有人发的文献 https://iopscience.iop.org/article/10.1088/1402-4896/ad14d9,Gallium phosphide (GaP) as a standard ultraviolet index detector: response comparison and measurements

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Frances Baines Admin The problem will be the same as with any other meter... it will be calibrated to a solar simulator, and hence should at least give "reasonable estimates" for sunlight (though I've played with several cheap ones that couldn't even manage that!) BUT they will all have slightly different spectral sensitivity, so as soon as the lamp spectrum differs from a solar simulator, you're VERY likely to get a different reading from the Solarmeter 6.5.. unless it also happens to have a sensitivity response very close to that for the erythemal action spectrum. Most cheap meters have AlGaN sensors which do not.

Quentin Dishman Moderator I don’t believe this is one of the ones that’s been tested extensively. Is its combined spectral response known? (Two separate graphs are included, presumably for two sensors, but UVI pertains to both) 4d

Quentin Dishman Moderator The more I think about it, the more skeptical I am that a two-sensor device would give comparable UVI readings between sunlight and artificial sources like a T5. Thomas Griffiths, Sarina Wunderlich ? 4d

Thomas Griffiths Moderator Quentin Dishman never seen this one! I think the biggest problem with a lot of these “alternatives” is the lack of cosine correction. How can we expect to get a good quality reading from something like a T5 when the sensor only sees in a beam shape? 4d

Sarina Wunderlich Quentin Dishman The meter won’t be able to calculate uvi from a uva and uvb sensor without knowing the spectrum.

David Horan

I have this one and a solar meter 6.5R. No comparison. This one is garbage

Donna Hazzlewood

· · Anyone know if this is a suitable solar meter, or do I require a reptile brand? Thanks

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Roman Muryn Admin There is I'm afraid confusion. The registered brand "Solarmeter" has a number of instrument which are designed to measure a number of sunlight wavelengths. In our group we are most interested in their model 6.5 which is associated with vitamin D3 facilitation. The unit of measure is UVi (UV index) BUT There are meters that measure sunlight or solar irradiation, these have been developed for the solar power industry and actually measure solar irradiation in w/m2. (Watts per square metre). It happens that they are also very useful in the reptile hobby because they give an indication of total power received from the sun. Furthermore, the model we use, the RS ISM 400 has been shown to be good at indicating Infrared produced by tungsten halogen lamps. Thus we can chose lamp strength in line with sunlight strength. The image you show is for a solar irradiation meter or Power Density meter, which measures in w/m2. In this group, we use the definition of sunlight based on ASTM G-173 at Atmospheric mass of 1.5. Do check that the above meter is calibrated to that standard, I'm certain that it will be, but check.

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Frances Baines Admin Hi, guys. I'm seeing a lot of photos taken with a tape measure blocking the meter, not just in this case but in several others citing a low output from lamps (not just Arcadia lamps). If the tape measure is held alongside the meter, it can shade out a considerable amount of the light from the lamp, because the meter sensor has a 180-degree field of view; if it cannot "see" the whole tube and fixture (as well as the bit directly above it) the reading will be low. HOWEVER there is one good photo - with the meter resting on the floor 17" below the lamp, reading UVI 2.2. THAT reading - assuming it is directly under the middle of the tube and aimed directly at the tube, and the items around the meter are not shading it, - is one I would trust, and YES that reading is about half what it should be - approximately UVI 4.0. Is this in an Arcadia T5-HO fixture? Not a look-alike from another brand? Does the writing on the "Arcadia" branding - the black writing - say this: D3+ REPTILE (the + sign is inside a circle) then underneath, !2%UVB OUTPUT LAMP. If it IS an Arcadia fixture, and a genuine Arcadia 12%UVB tube, there is a problem here. I would expect that output from a tube that says D3 REPTILE and 6%UVB OUTPUT LAMP. Half as strong! I agree with Thomas Griffiths - write down the batch number (the pale orange lettering at the other end from the "Arcadia" stamp. Also photograph the writing at both ends in sharp closeup focus, plus any receipts or proof of purchase etc, and your photos (especially the UVI 2.2 one) and contact Arcadia with these details and a covering letter.

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Lisa Jackson Author Thomas Griffiths already a noticeable difference! I took this reading within the 1st minute of turning it on! 😯

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Thomas Griffiths Moderator Lisa Jackson we’d be hoping to get around 3.8-4.3 when 17inches directly under the centre of the lamp after 100 hours of burning in, and once the lamp is settled with temperatures etc. So yes, this is much better already!!

Frances Baines Admin Great discussion. I use an Ocean Optics USB2000+ spectrometer for basic spectral analysis, this tells me the quality of the spectrum, i.e, the wavelengths present and their spectral power distribution. However, what it does not tell me is the shape of the beam and its penetration below the lamp, to the sides of the lamp, etc. i.e., the "quantity" of UV at different distances. For that I need a hand-held, portable meter like my Solarmeter 6.5. with which I can map the UV gradient. The spectrometer can only take a "snapshot" at a set distance. Because each "snapshot" requires the spectrometer to be calibrated, with a set procedure (adjusting the sensitivity, the scan time, the number of scans to be averaged; taking a dark spectrum to remove noise, etc) it is completely impractical to use a spectrometer to measure a UV gradient in a vivarium or in the field. The problem with converting a dslr camera would be the need to get it calibrated for absolute irradiance. Because the SiC sensors are maximally sensitive to the mid-VIS range and sensitivity drops right off to the UV and IR ends. Unless you compensate for this, you get completely weird spectra that are an integration of the lamp spectrum and the SiC sensors' sensitivity response. It usually looks like a bell curve - even with a halogen lamp, for example, which should look like a wedge rising up to the maximum into the IR.

Any recommendations on solarmeters that are

  • Accurate (within an acceptable tolerance);
  • Affordable (ideally sub-£50) I was quite surprised at the cost of most, so before I buy the cheapest one going which will likely be inaccurate, I'd like to see what others recommend for both accurate and value 🙂

Frances Baines Admin For many years, in the hope of finding an inexpensive substitute for the Solarmeter 6.5, we have tested cheap UVB meters and UV Index meters - the sort of thing that sun-tanners buy to take on holiday, typically under £100, and made in China. I had a small collection of the things at one time! ...All have proven impossible to use with artificial lighting because of the difference between the spectra of sunlight and lamps, with they can't resolve - and many are also wildly inaccurate with sunlight, too! This is usually because the spectral response of cheaper sensors includes UVA, the proportion of which varies greatly between lamps and sunlight. The meters in this image are all genuine Solarmeter 6.5 UV Index meters, which are scientific instruments made by Solar Light Company in the USA. They allow rebranding by ZooMed, Josh's Frogs and Lugarti which put their own labels on them, that's the only difference.

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《湿度》