New 100 Watt Lamps - Meter at 18. Is this normal?

[mstnt]

I have just relamped my level 1 beds. The beds are only one year old. I didn't meter the lamps when I first got the beds. Figured I would start now. The beds are 32 100 watt lamp units. The new lamps have about from 0 to 33 hours on them. For the canopy readings we are holding the meter center of the bed with the sensor apx 6" above the base. Acrylics are in. Top canopy readings are consistently in the 18's. For the bottom readings we are placing the sensor in the center directly on the acrylic (as if lying on the acrylic). Base readings are consistently in the 16's. We are letting the beds run 5 minutes so they have a chance to warm up. The lamps that I took out were metering in the 14's. These numbers seem really low compared to numbers I've seen on this site. Anyone care to share their readings?

[SUNNYDAYS]

The numbers you are seeing are a little low you may want to check the incoming voltage to your beds.

My 20 minute level 1 with Midday Suns in them with 25hours on them read:
5.0 25.7
6.0 3.8% UV B
7.0 17.9 mins to 4 meds


What lamp and beds do you have?

[solarmeter®]

What "percent UVB" are the lamps supposed to be?

The higher the percent B the lower a 5.0 meter will read for a given wattage lamp. It is not uncommon for some base bed high-B 100W's to read only 16-18 new. Old-era lamps sacrifice UVA (which is mostly what the 5.0 meter reads) to get more UVB (which is what the 6.0 meter reads).

Bottom line is your new lamps would be "hotter" on a 7.0 MED/hr meter and a 6.0 UVB meter for reddening rays... but not much better than the old ones for UVA tanning rays. Above 20 on a 5.0 would be more typical.

New-era lamps peaking at 365nm UVA read quite a bit higher on the 5.0, somewhat lower on a 6.0 UVB, and usually about the same as old-era on a 7.0 MED/hr meter.

[Din]

My 100W base beds (non reflectors) meter approx 30-35 with under 100 hours on them.

It does sound like a voltage issue.

What model/make bed is it?

[Rob]

I am not so sure its a voltage issue but it could be. You said that you beds were metering 14 with the old lamps.

My question is, what lamps were in the unit first off and what did you replace them with?

[solarmeter®]

The 30-35 sounds more like 100W new era lamps (9K-90, etc).

[SUNNYDAYS]

Dean

Those are some impressive numbers for 100 watt non reflector. What lamp is it and what bed are you using it in?

[Rob]

I put Phillips lamps in my sundash 232 (100 watt non reflector) and it metered 38 when they were new.

[solarmeter®]

Philips WHAT? Old-era peaking at 350nm or new era at 365nm?

Makes a big difference in 5.0 readings.



I can't keep track of which brands/models of lamps are old or new era anymore... but the new-era ones sometimes say "HP-like" output... meaning UVA peak near 365nm like the meter response also does.

[Rob]

Well, for one, you can't put new era lamps in older sundash equiment. They use magnetic ballast and they are not compatible.

I am not at the salon right now, but I think they were the swift.

[Din]

Originally Posted by SUNNYDAYS

Dean

Those are some impressive numbers for 100 watt non reflector. What lamp is it and what bed are you using it in?

Voltarc lamps....Dual Phosphorus lamps with the pink for the face area.

5.5% UVB....6.5% in the pink area.

I was surprised too.

When i metered the lamps at 600hours it was metering 22-24.

Not bad eh?

[SUNNYDAYS]

Not bad at all!!

[W8INLINE]

I "blame" the voltage for the high numbers. Those things are receiving 25 volts more than they are supposed to. I know for a fact that beds "behave" differently when they see 220v as opposed to 245v.

[Natureboy]

Originally Posted by solarmeter®

What "percent UVB" are the lamps supposed to be?

The higher the percent B the lower a 5.0 meter will read for a given wattage lamp. It is not uncommon for some base bed high-B 100W's to read only 16-18 new. Old-era lamps sacrifice UVA (which is mostly what the 5.0 meter reads) to get more UVB (which is what the 6.0 meter reads).

Bottom line is your new lamps would be "hotter" on a 7.0 MED/hr meter and a 6.0 UVB meter for reddening rays... but not much better than the old ones for UVA tanning rays. Above 20 on a 5.0 would be more typical.

New-era lamps peaking at 365nm UVA read quite a bit higher on the 5.0, somewhat lower on a 6.0 UVB, and usually about the same as old-era on a 7.0 MED/hr meter.

This is exactly right. My Sundash base beds I went from a 5% UVB lamp that metered 35 new to a 6.5% lamps that metered 25 new on a 5.0.

[solarmeter®]

And... that's why lamp distributors hated UV meters when they first came out. Some dumb ones still do. They would send out a batch of "hotter" lamps... only to be told by the customer that they meter too low. Damn meters!

But now that both 6.0 and 7.0 meters are in more common use, the smart ones (like John at URI) don't hate meters anymore.. because they can explain what's up accurately.

[mstnt]

The lamps are made by Voltarc for TanAmerica. They are the 5.0 SE's which is supposed to indicate the percent UVB. These are TanAmerica SantaBarbara's. I'll have to check the voltage.

[mstnt]

I don't know if this matters, but we have electronic ballasts in all the SB's.

[solarmeter®]

Well... those are medium B not high B - so you should be getting some more UVA reading on the 5.0 meter. However - I'm not sure Voltarcs are among the "strongest" choices for old-era lamps.

Find out if you're getting 230ish volts at the beds, or less. Don't get shocked in the process!

[mstnt]

I have to admit that I'm just learning about the differences in lamps and I rely TanAmerica to provide a quality product. Voltarc makes the lamps for TanAmerica. As I learn more, I'm sure that I will also be more discriminating in the future. As for checking the voltage - I'll have someone else do that. We have 208/230 in the building.

However, another reason that I was concerned about my readings is that I was told by a reputable source (John from URI) that since I have electronic ballasts in a bed that the lamp cooling system is originally engineered for magnetic ballasts that the lamps may be getting too much cooling, therfore not heating up enough to operate properly.

Has anyone else had that experience or heard of such a thing? If so, does anyone know what temperature the lamps need to heat up to operate properly? I know that there is an ideal ambient room temperature range that the manufacturer's recommend for the bed to operate properly. So it would seem to follow that the lamps would also have an ideal operating range and that is why there are cooling systems in beds for the lamps themselves. However, getting a consistent or verifiable answer on this has proven to be very difficult. TanAmerica's engineers and lamp "expert" have given me different answers as well as thier Voltarc rep. I would love to know what is the optimum temperature for a lamp to heat up to and maintain for tanning results.

This is something that I can field test with an infrared temperature reading device - which I do have available. So if anyone knows where I could find this information for the lamps I would greatly appreciate it.

Thanks

[solarmeter®]

John has posted that before.... but I forgot. Something like 110° as ideal. Below or above has lower UV output. Not a LOT - but some. Hopefully he will respond tomorrow.