Meter Quandry

solarmeter · 05-29-2002, 12:09 PM

Don,

Since it appears it will be yet another whole year until FDA switches from 156 J/m^2 per MED to 200 (or 180), people will have to apply conversion factors that much longer.

See post to John @ URI for example in Ballast thread. This is a pain in the ***, so I'm tempted to start setting model 7.0 at the 156 rate. However this would create confusion amongst people posting readings with different versions.

You have any opinion on this?

Steve

JOHN @ URI · 05-29-2002, 12:29 PM

Steve,
Could we send ours back to get done to the new standard. When ever they make up their minds.

Don Smith · 05-29-2002, 10:34 PM

Steve:

Barbara and I were talking about just that this morning. If you did make the "calculation denominator" 156 J/m2 and then FDA changed to 180, 200 or 210, could the meters then be sent back for recalibration?

FYI, we compared (1) the OLI spectroradiometer, (2) the OO spectroradiometer, (3) a 210 MED/hr meter, and, (4) the 200 MED/hr meter (in the case) you gave me to try. We considered the OLI to be the "gold standard" for this test. Here are the results for the te time (time to 4.0 MED) for two sunlamps in a test stand with the sensors at 10 cm from the bottom of the centerline of the sunlamps.

1. OLI = 41.5 minutes to 4.0 MED
2. OO = 42.4 minutes (adjusted from mW/cm2)
3. 210 = 42.2 minutes (adjusted X 1.35)
4. 200 = 42.0 minutes (adjusted X 1.28)

Thus, you can see that all of the meters were in very close agreement.

Not having to "remember" to make the conversion would be a big help (IMHO).

Finally, one of the nice features of the OO system is that we can change the "readout" from mW/cm2 to LUX and that gives us some new and exciting information.

Don

solarmeter · 05-29-2002, 10:57 PM

Don,

Thanks for the valuable intercomparison data. Happy to see the hand-held meters are keeping pace with the spectroradiometers. As you know, absolute spectral response is the key to that.

Yes, the model 7 solarmeters can be sent back for re-cal no problem. I'm debating doing that for free vs normal $30 charge, because I want accurate tools out there.

I'll email Sharon at FDA this thread and get her opinion as to when the calculation denominator will be finalized. Then decide on switching to 156 or hang on to 200. Ever since 2-8-02 I've been setting them at 200. Before that they were at 210. Geeeeze!

Steve

solarmeter · 06-05-2002, 12:02 PM

OK - decision made: Based on below message from FDA, it will be ~2 years before they change MED definition (subject to more feedback from the industry).

Therefore from today on, model 7.0 MED/hr will be set higher to the 156 J/m^2 existing MED value.

If anyone who has one wishes to send it back for free recal, address is on 'contact us' page of www.solarmeter.com . Will try to turn them around within 1 week, depending on how many come back.

Steve

________________ paste ____________________

Steve,

Since it will be at least a year before we propose changing to 200 J/m2 and then perhaps another year before it gets into the standard, I would suggest keeping it calibrated at 156 for now.

Sergio Coelho is my assistant and he probably will not do any measurements until I get a chance to work with him on it which may not be until next week. Sorry for the delay.

Sharon

Don Smith · 06-05-2002, 12:18 PM

Steve:

Good move! That will help end the "confusion" that exists today.

Will you also change the UVI meter or will you only change the MED/hour meter?

Don

solarmeter · 06-05-2002, 12:58 PM

Don - the UVI meter must remain as is, since NWS/NOAA bases it on mW/m^2 Eeff /25 rather than a specific J/m^2 definition. It just so happens to relate with WMO 210 J/m^2, so for outdoor use matches EPA guidelines.

Steve

bsmart · 06-05-2002, 11:04 PM

where can I purchase the 6.0 and 7.0 meters calibrated to the standards you mentioned here? I don't want to buy the 7.0 now and have to send it back for recal, but I do want to get one soon.

solarmeter · 06-06-2002, 12:12 AM

The regular models 5.0 and 6.0 are not affected by FDA MED/hr definition, so those you can call around to distributors for the best price: URI, 4-Seasons and others on 'distributor' page of website.

For a model 7.0 just email me to buy one here at the latest setting if you wish. When distributors re-order they will get latest setting as well. Thanks.

Solartech

bsmart · 06-06-2002, 12:59 PM

Solarmeter, I tried to email you but got undeliverable message. Is your system down??

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05-29-2002, 12:09 PM	#1 (permalink)
solarmeter Join Date: Nov 13 2001 Location: MI Posts: 631 Rep Power: 8	Don, Since it appears it will be yet another whole year until FDA switches from 156 J/m^2 per MED to 200 (or 180), people will have to apply conversion factors that much longer. See post to John @ URI for example in Ballast thread. This is a pain in the ***, so I'm tempted to start setting model 7.0 at the 156 rate. However this would create confusion amongst people posting readings with different versions. You have any opinion on this? Steve

05-29-2002, 12:29 PM	#2 (permalink)
JOHN @ URI I love Derf!! Join Date: Dec 21 2001 Location: Cleveland, Ohio Posts: 1,311 Rep Power: 7	Steve, Could we send ours back to get done to the new standard. When ever they make up their minds.

05-29-2002, 10:34 PM	#3 (permalink)
Don Smith Join Date: Feb 25 2000 Location: Tucson, AZ Posts: 1,619 Rep Power: 10	Steve: Barbara and I were talking about just that this morning. If you did make the "calculation denominator" 156 J/m2 and then FDA changed to 180, 200 or 210, could the meters then be sent back for recalibration? FYI, we compared (1) the OLI spectroradiometer, (2) the OO spectroradiometer, (3) a 210 MED/hr meter, and, (4) the 200 MED/hr meter (in the case) you gave me to try. We considered the OLI to be the "gold standard" for this test. Here are the results for the te time (time to 4.0 MED) for two sunlamps in a test stand with the sensors at 10 cm from the bottom of the centerline of the sunlamps. 1. OLI = 41.5 minutes to 4.0 MED 2. OO = 42.4 minutes (adjusted from mW/cm2) 3. 210 = 42.2 minutes (adjusted X 1.35) 4. 200 = 42.0 minutes (adjusted X 1.28) Thus, you can see that all of the meters were in very close agreement. Not having to "remember" to make the conversion would be a big help (IMHO). Finally, one of the nice features of the OO system is that we can change the "readout" from mW/cm2 to LUX and that gives us some new and exciting information. Don

05-29-2002, 10:57 PM	#4 (permalink)
solarmeter Join Date: Nov 13 2001 Location: MI Posts: 631 Rep Power: 8	Don, Thanks for the valuable intercomparison data. Happy to see the hand-held meters are keeping pace with the spectroradiometers. As you know, absolute spectral response is the key to that. Yes, the model 7 solarmeters can be sent back for re-cal no problem. I'm debating doing that for free vs normal $30 charge, because I want accurate tools out there. I'll email Sharon at FDA this thread and get her opinion as to when the calculation denominator will be finalized. Then decide on switching to 156 or hang on to 200. Ever since 2-8-02 I've been setting them at 200. Before that they were at 210. Geeeeze! Steve

06-05-2002, 12:02 PM	#5 (permalink)
solarmeter Join Date: Nov 13 2001 Location: MI Posts: 631 Rep Power: 8	OK - decision made: Based on below message from FDA, it will be ~2 years before they change MED definition (subject to more feedback from the industry). Therefore from today on, model 7.0 MED/hr will be set higher to the 156 J/m^2 existing MED value. If anyone who has one wishes to send it back for free recal, address is on 'contact us' page of www.solarmeter.com . Will try to turn them around within 1 week, depending on how many come back. Steve ________________ paste ____________________ Steve, Since it will be at least a year before we propose changing to 200 J/m2 and then perhaps another year before it gets into the standard, I would suggest keeping it calibrated at 156 for now. Sergio Coelho is my assistant and he probably will not do any measurements until I get a chance to work with him on it which may not be until next week. Sorry for the delay. Sharon

06-05-2002, 12:18 PM	#6 (permalink)
Don Smith Join Date: Feb 25 2000 Location: Tucson, AZ Posts: 1,619 Rep Power: 10	Steve: Good move! That will help end the "confusion" that exists today. Will you also change the UVI meter or will you only change the MED/hour meter? Don

06-05-2002, 12:58 PM	#7 (permalink)
solarmeter Join Date: Nov 13 2001 Location: MI Posts: 631 Rep Power: 8	Don - the UVI meter must remain as is, since NWS/NOAA bases it on mW/m^2 Eeff /25 rather than a specific J/m^2 definition. It just so happens to relate with WMO 210 J/m^2, so for outdoor use matches EPA guidelines. Steve

06-05-2002, 11:04 PM	#8 (permalink)
bsmart Join Date: May 2 2002 Location: 2621 W Main Suite 9 Posts: 769 Rep Power: 7	where can I purchase the 6.0 and 7.0 meters calibrated to the standards you mentioned here? I don't want to buy the 7.0 now and have to send it back for recal, but I do want to get one soon.

06-06-2002, 12:12 AM	#9 (permalink)
solarmeter Join Date: Nov 13 2001 Location: MI Posts: 631 Rep Power: 8	The regular models 5.0 and 6.0 are not affected by FDA MED/hr definition, so those you can call around to distributors for the best price: URI, 4-Seasons and others on 'distributor' page of website. For a model 7.0 just email me to buy one here at the latest setting if you wish. When distributors re-order they will get latest setting as well. Thanks. Solartech

06-06-2002, 12:59 PM	#10 (permalink)
bsmart Join Date: May 2 2002 Location: 2621 W Main Suite 9 Posts: 769 Rep Power: 7	Solarmeter, I tried to email you but got undeliverable message. Is your system down??

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