UVI Meter (Substitute of Solar Meter 6.5)

[kit0407]

I just got my UVI Meter. I think it works the same as the Solar Meter 6.5 but only cost half the price. USD98 in Amazon (I got it at USD51 in Hong Kong). Anyone who cannot afford a 6.5 can consider buying this. Hope this help

But I have a question about using these meter. When we measure, we need to hold it perpendicular to the UVB light. If we do so, the detector will not be in the same height with the tortoise. How can I get an accurate reading same height as the tortoise?

 

[ZEROPILOT]

The SOLARMETER 6.5 isn't as much of a brand name as it is the specific spectrum of 6.5 in UVB. Not UVI.
This may not be suitable.
Do you have any other information about it?

 

[kit0407]

Oh I see! This is the label behind the meter. The Response 280-400nm is the same as the Solar Meter 6.5. Does this indicate the spectrum?

Thank you for clarifying

 

[jaizei]

The SOLARMETER 6.5 isn't as much of a brand name as it is the specific spectrum of 6.5 in UVB. Not UVI.
This may not be suitable.
Do you have any other information about it?

the 6.5 measures UVI

Oh I see! This is the label behind the meter. The Response 280-400nm is the same as the Solar Meter 6.5. Does this indicate the spectrum?

Thank you for clarifying

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View attachment 367777

That type of meter is not as accurate as a 6.5.

https://www.licht-im-terrarium.de/_media/mess/uv-index_meter_testreport.pdf

 

[kit0407]

Thank you I am reading through the comparison! This is the comparison I was looking for. But does that mean the Solarmeter 6.5 itself fluctuate regarding the readings? This graph compares six Solarmeter 6.5, and the readings defer a lot.

 

[Alex and the Redfoot]

Yes, for the UVB LED sources measurements are very different. I think this relates more to the LED lamps than to Solarmeter (different spectral charts, the LEDs are pretty small and maybe require very precise positioning of radiometer). It was a "draft research" on the conference.

6.5R models are in the middle ground, they are a bit newer than 6.5, so may have a bit different calibration or sensor/lens.

This test unfortunately does not include popular T5HO lamp models..

You may compare reading from your radiometer with readings done with Solarmeter for your UVB lamp (there should be plenty of them) to get an idea of measurement difference. Sensor should be pointed straight up, under the exact center of the lamp, no tilt. You'll have to clean substrate at the measurement point to measure UVI at "tortoise level".

 

[kit0407]

the 6.5 measures UVI



That type of meter is not as accurate as a 6.5.

https://www.licht-im-terrarium.de/_media/mess/uv-index_meter_testreport.pdf

Just finish reading it🙌🏻 What I want to point out is, is it worth buying as a reference IF people does not want to buy a USD249 Solarmeter 6.5? Is it better than having nothing? Is it better than a 6.2?

From the research, I noticed that the longer the distance between the meter and the UVB light, the less differentiation between the two meters. For example in a 30-50cm distance (which is the common distance for lamp fixture): 1.3 vs 1.1 / 0.7 vs 0.6 / 1.5 vs 1.2

I think it's still worth as a reference taking into account that the solarmeter 6.5 is not 100% accurate itself. The Ferguson Zone is a range for example Zone III Average exposure: UVI 1.0-2.6. We can use it as a reference to see if it is more or less within that range.

Yes, for the UVB LED sources measurements are very different. I think this relates more to the LED lamps than to Solarmeter (different spectral charts, the LEDs are pretty small and maybe require very precise positioning of radiometer). It was a "draft research" on the conference.

6.5R models are in the middle ground, they are a bit newer than 6.5, so may have a bit different calibration or sensor/lens.

This test unfortunately does not include popular T5HO lamp models..

You may compare reading from your radiometer with readings done with Solarmeter for your UVB lamp (there should be plenty of them) to get an idea of measurement difference. Sensor should be pointed straight up, under the exact center of the lamp, no tilt. You'll have to clean substrate at the measurement point to measure UVI at "tortoise level".

I thought they were using the same lamp to test. Thank you Alex for your advice!

 

[Alex and the Redfoot]

They've used several lamps for testing.. Including very "exotic" ones like "old metal hallide" But not popular T5. Maybe there are other reports on the site.. Need to check, armed with Google Translate..

I can't be compared with a Solarmeter 6.2 (this measures mW/cm2, which can be converted fo UVI with some math, and spectral charts or comparison tables).

About usefulness - it's like having a ruler with 1±0.001cm precision and a ruler with 0.99±0.04cm precision ) Better than nothing, I think. Especially, if you do some "calibration" comparing your result to Solarmeter 6.5 measurements of the same lamp model. There will be some inaccuracy, but I hope, tolerable. Much better than UV test cards.

 

[jaizei]

Just finish reading it🙌🏻 What I want to point out is, is it worth buying as a reference IF people does not want to buy a USD249 Solarmeter 6.5? Is it better than having nothing? Is it better than a 6.2?

From the research, I noticed that the longer the distance between the meter and the UVB light, the less differentiation between the two meters. For example in a 30-50cm distance (which is the common distance for lamp fixture): 1.3 vs 1.1 / 0.7 vs 0.6 / 1.5 vs 1.2

I think it's still worth as a reference taking into account that the solarmeter 6.5 is not 100% accurate itself. The Ferguson Zone is a range for example Zone III Average exposure: UVI 1.0-2.6. We can use it as a reference to see if it is more or less within that range.

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View attachment 367784


I thought they were using the same lamp to test. Thank you Alex for your advice!

I wouldn't rely on a meter like this, but then again I've had solarmeters since the 6.2 was the 'standard,' so i'm biased. The most fluctuations for the solarmeters was testing an LED that was mostly outside of the listed spectral response of the meter (peak 275 vs 280-400). The other tests had the solarmeters close (±12% of mean) to within the specs (±10%).

The 'problem' with UVI meters is that they're treated as though they indicate whether a bulb is 'safe,' when in reality they are primarily useful for determining if a known 'safe' bulb is being used safely and is still effective. The R>>G meter being more responsive to longer wavelength UVB up to UVA makes it less suitable for that purpose. It being less responsive to the shorter wavelength UVB could be compounded if used with a UVB bulb of unknown safety since cheaper UVB bulbs may produce shorter wavelength UVB in order to 'perform' better on 6.5 and UVI meters. ie, 6.5 is the current 'test' for UVB bulbs and some bulbs are produced to look good on that test without understanding that their spectrum is unnatural/nonterrestrial and can be dangerous.

They've used several lamps for testing.. Including very "exotic" ones like "old metal hallide" But not popular T5. Maybe there are other reports on the site.. Need to check, armed with Google Translate..

I can't be compared with a Solarmeter 6.2 (this measures mW/cm2, which can be converted fo UVI with some math, and spectral charts or comparison tables).

About usefulness - it's like having a ruler with 1±0.001cm precision and a ruler with 0.99±0.04cm precision ) Better than nothing, I think. Especially, if you do some "calibration" comparing your result to Solarmeter 6.5 measurements of the same lamp model. There will be some inaccuracy, but I hope, tolerable. Much better than UV test cards.

She also posts in the Reptile Lighting Group, I just linked a version that was hosted on her site so that it was more accessible.

Using a 6.2 and converting to UVI is tricky. imo, the most usefulness of the ratio between UVB and UVI is making an educated guess about the spectrum of an unknown bulb and whether it's weighted towards shorter wavelength UVB. It's cheaper than buying a spectrometer.

Generally, 6.2 and 6.5 meters are best used at tracking the same thing over time vs comparing readings of different things, esp measured by different meters. A potential ±10% between 2 solarmeters compounding whatever the differences between 2 bulbs (probably at least ±10%) can quickly skew the results.

 

[Alex and the Redfoot]

I wouldn't rely on a meter like this, but then again I've had solarmeters since the 6.2 was the 'standard,' so i'm biased. The most fluctuations for the solarmeters was testing an LED that was mostly outside of the listed spectral response of the meter (peak 275 vs 280-400). The other tests had the solarmeters close (±12% of mean) to within the specs (±10%).

The 'problem' with UVI meters is that they're treated as though they indicate whether a bulb is 'safe,' when in reality they are primarily useful for determining if a known 'safe' bulb is being used safely and is still effective. The R>>G meter being more responsive to longer wavelength UVB up to UVA makes it less suitable for that purpose. It being less responsive to the shorter wavelength UVB could be compounded if used with a UVB bulb of unknown safety since cheaper UVB bulbs may produce shorter wavelength UVB in order to 'perform' better on 6.5 and UVI meters. ie, 6.5 is the current 'test' for UVB bulbs and some bulbs are produced to look good on that test without understanding that their spectrum is unnatural/nonterrestrial and can be dangerous.





She also posts in the Reptile Lighting Group, I just linked a version that was hosted on her site so that it was more accessible.

Using a 6.2 and converting to UVI is tricky. imo, the most usefulness of the ratio between UVB and UVI is making an educated guess about the spectrum of an unknown bulb and whether it's weighted towards shorter wavelength UVB. It's cheaper than buying a spectrometer.

Generally, 6.2 and 6.5 meters are best used at tracking the same thing over time vs comparing readings of different things, esp measured by different meters. A potential ±10% between 2 solarmeters compounding whatever the differences between 2 bulbs (probably at least ±10%) can quickly skew the results.

Thank you! I wish I can explain things that clear!

To add a little context, OP has an Arcadia 14% lamp with a meshed top terrarium. So this meter is to be used to assess the correct distance and UV output degradation over time. So I thought if we can determine the "delta" between Solarmeter measurements of the same lamp model and R>>G meterings we can rely on this data...

 

[Markw84]

In several conversations with the developer of the solarmeter, he explained the sensor used in the meter alone is over $100 wholesale cost. They try to get the cost of their meter as affordable as possible, but the accuracy of the sensor is paramount. The algorithm used is also a big part of the meter's accuracy in determining UVI as it pertains to reptiles. Theirs is specifically weighted to the bioactive wavelengths around 295nm. All other "reasonable priced" meters are sensitive to a much wider spectrum - well into the UVA, longer, wavelengths. As many fluorescent bulbs age, it can be the shorter wavelengths lost first in output. So meters picking up the longer wavelengths will still read a much higher UVI than a solarmeter, since it is the bioactive wavelengths that tend to be lost first. Since the UVB bulbs we buy put out much more UVA than UVB, this can really skew reading and give a false indication that the bulb is still OK.

When reading a dangerous bulb with too much short wavelength output, even UVC, this can also be masked with a cheaper meter by the much greater output of UVA bulbs produce overshadowing the smaller, but dangerous amounts of short UVB or UVC.

 

[kit0407]

In several conversations with the developer of the solarmeter, he explained the sensor used in the meter alone is over $100 wholesale cost. They try to get the cost of their meter as affordable as possible, but the accuracy of the sensor is paramount. The algorithm used is also a big part of the meter's accuracy in determining UVI as it pertains to reptiles. Theirs is specifically weighted to the bioactive wavelengths around 295nm. All other "reasonable priced" meters are sensitive to a much wider spectrum - well into the UVA, longer, wavelengths. As many fluorescent bulbs age, it can be the shorter wavelengths lost first in output. So meters picking up the longer wavelengths will still read a much higher UVI than a solarmeter, since it is the bioactive wavelengths that tend to be lost first. Since the UVB bulbs we buy put out much more UVA than UVB, this can really skew reading and give a false indication that the bulb is still OK.

When reading a dangerous bulb with too much short wavelength output, even UVC, this can also be masked with a cheaper meter by the much greater output of UVA bulbs produce overshadowing the smaller, but dangerous amounts of short UVB or UVC.

"Theirs is specifically weighted to the bioactive wavelengths around 295nm." Do you mean the Spectral Response 280-400nm stated behind their meter? Or it's something more than that?

UVI is a standard international indicator. So if both meter measures UVI, then the algorithm should be the same... sorry was very confused🙈

 

[jaizei]

"Theirs is specifically weighted to the bioactive wavelengths around 295nm." Do you mean the Spectral Response 280-400nm stated behind their meter? Or it's something more than that?

View attachment 367798

"Spectral Sensitivitites" on page 5 of the PDF from earlier in the thread

 

[kit0407]

"Spectral Sensitivitites" on page 5 of the PDF from earlier in the thread

OK thank you for all your patience explaining to me😆🙌🏻 I understand more now🙏🏻

 

[Alex and the Redfoot]

OK thank you for all your patience explaining to me😆🙌🏻 I understand more now🙏🏻

Thanks for bringing this topic up! It was worth trying (I can get Solarmeter for 300$ + delivery )

And, yes, I've gained better understanding and valuable information, which is priceless

 

[ZEROPILOT]

OK thank you for all your patience explaining to me😆🙌🏻 I understand more now🙏🏻

So do I, actually