Lighting Grow Northern Live Tech Talk

[HubbaBubba]

Sorry I missed this one. In regards to the output spectrum of the HS1, it hasn't changed since launch. We are very happy with its performance in the current light engine configuration. Regardless of what your eye or a camera sees this is the irradiance vs wavelength data of every unit we have produced so far:

What is the output supposed to be in Lumens or PARs?

Today my HS1 is dim... it has dropped to 30% of normal, and there is less heat coming out the vents. The voltage in is 235V.

A light meter shows 5000 lumens at 30cm directly under the diffuser.
Last time I checked it was 15000 lumens at 35 cm, that is a BIG drop. Something is wrong but all the LEDs are lit.

Yes, the measurment is not accurate because red and blue LEDS put out more than half of the light, but it is a reference point.

For comparison (because a normal human doesn't know or care what a lumen is):
...direct sun is 70000
outdoor shade 13000
HS1 at 30 cm is 5000

 

[GrowNorthern]

Looking at your data in lumens- Yes if you measured correctly it could be showing that the light is dimming itself. Another way of seeing this is putting the light in a room with no other lights and aiming it at a wall. If you notice that the light on the wall is flickering that usually means the unit is auto dimming. You can also take the lid of the unit when it is down at 5,000 lumens and see if this then raises the output back to the initial start up reading. Either way if you think you have an issue with the light please contact us at warranty@grownorthern.co.uk. I think it may be that you require the new lid we are producing with extra ventilation.

In regards to your comparison, as you see in my previous post 75%+ irradiance is at 650-660nm which is absorbed at a much higher rate than most light in a blackbody spectrum even though a blackbody spectrum will give much higher PAR and Lumen readings.

If all lights where measure by weighted PAR or PPFD measured at several points across a coverage area then we would give you some data to compare but they're not. Therefore anything we release will look poor in comparison with non uniform TIR LED grow lights which are measured in their central hotspot even though our lights are way more efficient than most products on the market and the narrow band spectra and uniform coverage produce a much higher quality end product. Our monochromatic LED's are measured in radiometric power and the data is available on our website http://www.grownorthern.com/gn-rebel.

 

[dankmeaway]

thanks for the great info.

 

[HubbaBubba]

Looking at your data in lumens- Yes if you measured correctly it could be showing that the light is dimming itself. Another way of seeing this is putting the light in a room with no other lights and aiming it at a wall. If you notice that the light on the wall is flickering that usually means the unit is auto dimming. You can also take the lid of the unit when it is down at 5,000 lumens and see if this then raises the output back to the initial start up reading. Either way if you think you have an issue with the light please contact us at warranty@grownorthern.co.uk. I think it may be that you require the new lid we are producing with extra ventilation.

Thank you for the very fast reply.

I think you are saying the HS1 gets hot and shuts down... keep it cool and it might start to work properly again?

My grow room is air conditioned at a steady 27C and 40% humidity measured at the height of the HS1. Pretty sweet conditions for electronics. Could it really be overheating?

Ok, I will play weekend electrician with 220v (don't laugh Americans, 220V hurts a lot more than 110V)

The cover is off, the cooling fins are not even warm. No change in light output, no sign of flickering.
What else can I try? Is there a reset button. Has the overheat sensor failed?

 

[GrowNorthern]

It could be an issue with the NTC (sensor) but more likely a programming error or measurement error. Typically If the HS1 is in an ambient of 40-50C, the auto dimming lowers the current between 1-10% over 10C and if the temp continues to rise the unit will shut off. However the flickering is very clear to see and you are saying there is a 70% reduction in a 27 degree ambient with no flickering. I can see from the picture also your unit is from our last production batch (HS1.1) which means it has the extra ventilation so it will not be a physical heat issue.

This leaves us with 2 possibilities either there has been a programming issue/driver issue or the measurement is incorrect.

Please describe the conditions in which you took the 15k lumen output reading. For example;
Is it just as you turn the light on every time or after its been off for a few hours?
What diffuser to you have?
Are you taking the measurements from the exact same location?
What is the time taken to go from 15k to 5k lumen output from start up?.

Even high accuracy quantum sensors have great trouble with measuring artificial lights especially monochromatic LED's. You are measuring monochromatic LED's with a lumen meter which I can safely is not what it was designed to do. PAR sensors only have 90% accuracy when specifically designed to measure LED's it could be the case a very small variable with an insufficient measurement tool can give rise to large changes in data.

 

[GrowNorthern]

Additionally, I think what is happening is when your lumen meter is first turned on it is giving you an incorrect reading because of the blue and Deep red LED's. I think 5-6000 lumens is accurate reading of the highlighted output bandwidth in the black box below

Your lumen sensor after being turned on is constantly adjusting to give a more accurate read out but it is just not built to measure the emission peaks outside of the highlighted bandwidth.

 

[HubbaBubba]

I appreciate your concern that I am measuring wrong.
I stick the light meter directly under the middle of the Diffuser at 30cm, the reading is stable. This is not rocket science.

There is a dramatic drop in light output. It is obvious and consistent and very noticeable with the naked eye.
My HS1 is always on, 24/7 since installation.
Suddenly yesterday the output dropped to 1/3 of full power.
I am measuring directly under the center of the diffuser, the diffuser is 60x90.
How would you suggest that customers more objectively quantify the light output?

Do you have a simple light meter handy? We could compare numbers.
Or we could both download a light meter App for our smartphones and compare readings.

Let's keep this simple, skip the "high accuracy quantum sensors"

 

[HubbaBubba]

It could be an issue with the NTC (sensor)

What is an NTC? Sometimes acronyms don't help, they obfuscate.

What would you accept as evidence that my HS1 has a problem?
Does this photo help?
That is the HS1 only 15cm away from two seedlings. Normally they seedlings like 45cm.

 

[TaNg]

The

I appreciate your concern that I am measuring wrong.
I stick the light meter directly under the middle of the Diffuser at 30cm, the reading is stable. This is not rocket science.

There is a dramatic drop in light output. It is obvious and consistent and very noticeable with the naked eye.
My HS1 is always on, 24/7 since installation.
Suddenly yesterday the output dropped to 1/3 of full power.
I am measuring directly under the center of the diffuser, the diffuser is 60x90.
How would you suggest that customers more objectively quantify the light output?

Do you have a simple light meter handy? We could compare numbers.
Or we could both download a light meter App for our smartphones and compare readings.

Let's keep this simple, skip the "high accuracy quantum sensors"

The guy is trying to help you and you come back with sarcasm? Very mature! I personally think you want there to be a problem with your light,seems that way from your posts in this thread.

 

[HubbaBubba]

The


The guy is trying to help you and you come back with sarcasm? Very mature! I personally think you want there to be a problem with your light,seems that way from your posts in this thread.

Ok, so the burden is on me to prove there is a problem with my HS1.
I have offered measurements and photos.

How else can I meet that burden of proof?
The implication was, and I am quoting Grownorthern, "high accuracy quantum sensors" couldn't do it.

Even high accuracy quantum sensors have great trouble with measuring artificial lights especially monochromatic LED's.

Really? This isn't a Star Trek warp core. It is a light.
Can't we use a simple light meter to compare before the problem and after the problem?
Maybe I misunderstood but it seemed like Grownorthern was trying to with bluster with technobabble.

Part of this is my fault for not having a watt meter to measure power consumption. I suspect my HS1 is consuming less than 30 watts, will know soon.

There is a big genuine problem with my HS1. Not a poor venting issue, or a warped diffuser, or a chip in the paint.