Date: Sun, 20 Jun 2010 11:58:55

Author: Urs Lauterburg

Subject: Re: Blackbody radiation experiments with light bulbs

Post:

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Jerry man,

Thank you so much for communicating more details about the OO
spectrometer types. Your information will help me to find a suitable
one. It will be the best balance between cost and specifications.
Because my demonstration apparatus area has reached the storage
capacity I prefer to shell out more for good pieces of equipment than
a large amounts of short living and momentary voluminous junk.

I'll try to keep you up to date with what I finally acquired.

Best regards and all

Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland

>Urs,
>
>I am not sure which model to recommend today because they've really
>changed and improved and they have many more models since I acquired
>mine many years ago. The one I have was given to me by the
>Astronomy group who had used it with a telescope.
>
>I have the model USB 2000 and it is great. There is also a model USB
>2000 with a fiber optic I have no real need for the fiber optic.
>
>So I must recommend that you start by looking at the USB 2000 model.
> And also consider the USB 650 model that is much less expensive and
>is for made education and it can interface to the Pasco and the
>Vernier systems.
>
>Note that it easily saturates from even a low intensity lamp. So I
>have added a manually adjustable mechanical aperture to control the
>intensity and prevent saturation. You could do the same thing with
>variable polarizers or variable thickness neutral density filters.
> They have a great model spectrometer with an electronic shutter
>that is really fantastic for automatically controlling and
>preventing saturation but it is pricey, above $6000 US dollars I
>think. - Jerry
>
>
>
>On Sat, Jun 19, 2010 at 10:22 AM, Urs Lauterburg
>
>wrote:
>
>Brian, Jerry, Cliff et al.,
>
>OK, I think I have to get one of these OO-spectrometers too now.
>Specially if it let's you do the blackbody radiation quantitatively.
>I would also like to be able to acquire and display the measurements
>with LabVIEW on my Mac Pro in the auditorium if possible. If the
>wavelength dependent sensitivity of the device is known and if it
>has a serial or USB interface with a known protocol it should be
>possible. It would be very nice to show the redward shift upon
>dimming a suitable radiation source. Maybe looking directly at a
>carbon arc lamp would be best to minimize the absorption effects of
>glass housing etc. Would a neutral density filters have the same
>affect as lowering the temperature? I am not sure.
>
>I think it's time to acquire an OO device. Jerry has advertised them
>several times over the past years and I am starting to believe him.
>Are OOs spectrometers the best and the most versatile ones? What
>type should I get if quality matters even more then the initial cost?
>
>Like Cliff I take my hat off to those who do absolute photometry ;-)
>
>Thank you for suggestions and comments
>
>
>Urs
>
>Urs Lauterburg
>Physics demonstrator
>Physikalisches Institut
>University of Bern
>Switzerland
>
>>After reading Cliff's response I looked at the OObase web sight I
>>just now discovered that in 2006 there was a free spectral
>>correction software for the OObase model USB2000, USB4000 and
>>USB650 spectrometers:
>>
>
>Free spectral correction software from Dr. Charles Mazel at
>www.nightsea.com.
>
>
>http://www.synbio.org.uk/component/content/article/46-instrumentation-news/1221-ocean-optics-spectrometer.html?directory=257
>
>Perhaps this software is still available in 2010?
>
>
>
>
>And it may still be available in 3010? - JZ
>
>
>
>On Wed, Jun 16, 2010 at 8:56 AM, Cliff Bettis
> wrote:
>
>The sensor for the Blackbody experiment in the Pasco version is a
>thermopile which presumably has a flat response. The results you get
>are OK but not to the point of being quantitative. The peak
>wavelength for the incandescent bulb shows up at about 1000 nm and
>if you lower the voltage to the bulb, the peak drops and shifts
>redward. However trying to integrate under the distribution curve to
>show the 4th power dependence on temperature doesn't work so well.
>
>My experimental hat is off to those people who do absolute photometry.
>
>Cliff
>
>From: tap-l-owner@lists.ncsu.edu
>[mailto:tap-l-owner@lists.ncsu.edu]
>On Behalf Of Zani, Gerald
>Sent: Wednesday, June 16, 2010 7:31 AM
>To: tap-l@lists.ncsu.edu
>Subject: Re: [tap-l] Blackbody radiation experiments with light bulbs
>
>Brian,
>
>I also noticed the blue-skewed results with the OO spectrometer and
>clear filament incandescent lamp demo.
>
>I too am interested in the same question will be looking at the
>wavelength the dependent corrections to the emissivity of the lamp
>filament.
>
>I have two TPT articles on lamp filament temperatures: "Temperature
>of a Light Bulb Filament" and "Basic Physics of the Incandescent
>Lamp".
>
>Particularly, look at sidebar 1 in the second TPT article, Basic
>Physics of the Incandescent Lamp. - JZ
>
>On Tue, Jun 15, 2010 at 5:30 PM, Paul Nord
> wrote:
>
>How is the gain corrected for the spectral sensitivity of various wavelengths?
>http://www.oceanoptics.com/technical/detectorsonyILX511.pdf
>The response of the CCD is surely not uniform over the entire range
>of sensitivity.
>
>What happens if you do this without the fiber?
>
>Have you tried a clear incandescent?
>
>I would have expected the heat lamp to tend toward the infrared. But
>your results look similar to the frosted bulb.
>
>
>Have you tried fitting the entire spectrum to a black body curve?
>
>Are you measuring current? voltage? Resistance will change a lot
>with the temperature of the filament.
>
>Paul
>
>
>
>On Jun 15, 2010, at 3:59 PM, Cudnik,Brian wrote:
>
>> Good afternoon-
>>
>> We tried out, with a group of education majors, for the first time an
>> experiment that demonstrates the laws of blackbody radiation, using an
>> incandescent light bulb, a variable transformer, an Ocean Optics
>> fiber-optic spectrometer and a PASCO Xplorer GLX. We varied the voltage
>> received by the bulb and recorded the spectral curve in each of five
>> cases (30%, 40%, 60%, 80%, and 100% full power). We measured the peak
>> wavelength of the curve, with which we calculated the temperature.
>>
>> In all cases, the temperature came out too hot (except for the solar
>> case below where I aimed the spectrometer through a window at a cloud
>> low on the horizon), since tungsten melts at 4600K and most bulbs
>> operate at between 2000 and 3200K. What physical property of the light
>> bulb could cause the radiation curve to skew blue-ward? Perhaps it is
>> due the glass casing blocking most of the infrared?
>>
>> The fiber transmission is flat (80% relative transmission) from 450nm to
>> 1050nm). Thanks!
>>
>> Lambda(nm) lambda m T, K
>> 250W heat lamp, clear
>> 692.87 6.929E-07 4183
>> 699.29 6.993E-07 4144
>> 663.24 6.632E-07 4369
>> 650.54 6.505E-07 4455
>> 628.77 6.288E-07 4609
>>
>> 75W incandescent bulb, frosted
>> 714.90 7.149E-07 4054
>> 693.63 6.936E-07 4178
>> 635.66 6.357E-07 4559
>> 633.20 6.332E-07 4577
>> 622.40 6.224E-07 4656
>>
>> reference values
>> 1000.0 1.000E-06 2898
>> 900.0 9.000E-07 3220
>> 800.0 8.000E-07 3623
>> 750.0 7.500E-07 3864
>> 700.0 7.000E-07 4140
>> 650.0 6.500E-07 4458
>> 600.0 6.000E-07 4830
>> 550.0 5.500E-07 5269
>> 500.0 5.000E-07 5796
>> 450.0 4.500E-07 6440
>> 400.0 4.000E-07 7245
>>
>> Sun peak wavelength = 501nm (5780 surface temperature)
>> Measured
>> 559.9 5.599E-07 5176
>>

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Jerry man,

Thank you so much for communicating more details about the OO
spectrometer types. Your information will help me to find a suitable
one. It will be the best balance between cost and specifications.
Because my demonstration apparatus area has reached the storage
capacity I prefer to shell out more for good pieces of equipment than
a large amounts of short living and momentary voluminous junk.

I'll try to keep you up to date with what I finally acquired.

Best regards and all

Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland

Urs,

I am not sure which model to recommend
today because they've really changed and improved and they have many
more models since I acquired mine many years ago. The one I have
was given to me by the Astronomy group who had used it with a
telescope.

I have the model USB 2000 and it is
great. There is also a model USB 2000 with a fiber optic I have no
real need for the fiber optic.

So I must recommend that you start by
looking at the USB 2000 model. And also consider the USB 650
model that is much less expensive and is for made education and it can
interface to the Pasco and the Vernier systems.

Note that it easily saturates from even a
low intensity lamp. So I have added a manually adjustable
mechanical aperture to control the intensity and prevent saturation.
You could do the same thing with variable polarizers or
variable thickness neutral density filters. They have a
great model spectrometer with an electronic shutter that is really
fantastic for automatically controlling and preventing saturation but
it is pricey, above $6000 US dollars I think. -
Jerry




On Sat, Jun 19, 2010 at 10:22 AM, Urs
Lauterburg wrote:
Brian, Jerry, Cliff et al.,

OK, I think I have to get one of these OO-spectrometers
too now. Specially if it let's you do the blackbody radiation
quantitatively. I would also like to be able to acquire and display
the measurements with LabVIEW on my Mac Pro in the auditorium if
possible. If the wavelength dependent sensitivity of the device is
known and if it has a serial or USB interface with a known protocol it
should be possible. It would be very nice to show the redward shift
upon dimming a suitable radiation source. Maybe looking directly at a
carbon arc lamp would be best to minimize the absorption effects of
glass housing etc. Would a neutral density filters have the same
affect as lowering the temperature? I am not sure.

I think it's time to acquire an OO device. Jerry has advertised them
several times over the past years and I am starting to believe him.
Are OOs spectrometers the best and the most versatile ones? What type
should I get if quality matters even more then the initial cost?

Like Cliff I take my hat off to those who do absolute photometry
;-)

Thank you for suggestions and comments


Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland
After reading Cliff's response I looked
at the OObase web sight I just now discovered that in 2006 there was a
free spectral correction software for the OObase model USB2000,
USB4000 and USB650 spectrometers:




Free spectral correction software from Dr. Charles Mazel
at www.nightsea.com.


http://www.synbio.org.uk/component/content/article/46-instrumentation-news/1221-ocean-optics-spectrometer.html?directory=3D257

Perhaps this software is still available in 2010?




And it may still be available in 3010? - JZ



On Wed, Jun 16, 2010 at 8:56 AM, Cliff Bettis
wrote:
The sensor for the Blackbody experiment in the Pasco
version is a thermopile which presumably has a flat response. The
results you get are OK but not to the point of being quantitative. The
peak wavelength for the incandescent bulb shows up at about 1000 nm
and if you lower the voltage to the bulb, the peak drops and shifts
redward. However trying to integrate under the distribution curve to
show the 4th power dependence on temperature doesn=B9t work so
well.

My experimental hat is off to those people who do absolute
photometry.

Cliff

From: tap-l-owner@lists.ncsu.edu
[mailto:tap-l-owner@lists.ncsu.edu] On Behalf Of Zani, Gerald
Sent: Wednesday, June 16, 2010 7:31 AM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] Blackbody radiation experiments with light
bulbs

Brian,

I also noticed the blue-skewed results with the OO
spectrometer and clear filament incandescent lamp demo.

I too am interested in the same question will be looking
at the wavelength the dependent corrections to the emissivity of the
lamp filament.

I have two TPT articles on lamp filament temperatures:
"Temperature of a Light Bulb Filament" and "Basic
Physics of the Incandescent Lamp".

Particularly, look at sidebar 1 in the second TPT article,
Basic Physics of the Incandescent Lamp. - JZ

On Tue, Jun 15, 2010 at 5:30 PM, Paul Nord
wrote:

How is the gain corrected for the spectral sensitivity of
various wavelengths?
http://www.oceanoptics.com/technical/detectorsonyILX511.pdf
The response of the CCD is surely not uniform over the entire range of
sensitivity.

What happens if you do this without the fiber?

Have you tried a clear incandescent?

I would have expected the heat lamp to tend toward the infrared. But
your results look similar to the frosted bulb.


Have you tried fitting the entire spectrum to a black body curve?

Are you measuring current? voltage? Resistance will change a lot with
the temperature of the filament.

Paul



On Jun 15, 2010, at 3:59 PM, Cudnik,Brian wrote:

> Good afternoon-
>
> We tried out, with a group of education majors, for the first
time an
> experiment that demonstrates the laws of blackbody radiation,
using an
> incandescent light bulb, a variable transformer, an Ocean
Optics
> fiber-optic spectrometer and a PASCO Xplorer GLX. We varied the
voltage
> received by the bulb and recorded the spectral curve in each of
five
> cases (30%, 40%, 60%, 80%, and 100% full power). We measured the
peak
> wavelength of the curve, with which we calculated the
temperature.
>
> In all cases, the temperature came out too hot (except for the
solar
> case below where I aimed the spectrometer through a window at a
cloud
> low on the horizon), since tungsten melts at 4600K and most
bulbs
> operate at between 2000 and 3200K. What physical property of the
light
> bulb could cause the radiation curve to skew blue-ward? Perhaps
it is
> due the glass casing blocking most of the infrared?
>
> The fiber transmission is flat (80% relative transmission) from
450nm to
> 1050nm). Thanks!
>
> Lambda(nm) lambda m T, K
> 250W heat lamp, clear
> 692.87 6.929E-07 4183
> 699.29 6.993E-07 4144
> 663.24 6.632E-07 4369
> 650.54 6.505E-07 4455
> 628.77 6.288E-07 4609
>
> 75W incandescent bulb, frosted
> 714.90 7.149E-07 4054
> 693.63 6.936E-07 4178
> 635.66 6.357E-07 4559
> 633.20 6.332E-07 4577
> 622.40 6.224E-07 4656
>
> reference values
> 1000.0 1.000E-06 2898
> 900.0 9.000E-07 3220
> 800.0 8.000E-07 3623
> 750.0 7.500E-07 3864
> 700.0 7.000E-07 4140
> 650.0 6.500E-07 4458
> 600.0 6.000E-07 4830
> 550.0 5.500E-07 5269
> 500.0 5.000E-07 5796
> 450.0 4.500E-07 6440
> 400.0 4.000E-07 7245
>
> Sun peak wavelength =3D 501nm (5780 surface temperature)
> Measured
> 559.9 5.599E-07 5176
>






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