John is correct. The mount is, indeed, a Spindler & Hoyer Gottingen, made in Germany. I also think he is correct about what the 'thing' is. Measuring the voltage from the unit with the 7081 with aluminium tape over the front, I get pretty close to 0.0 uV. With the tape removed and the lights on in the shop, I get about 2 uV. With a small, three AAA battery powered, LED flashlight illuminating it from close range, I get about 280 uV. I am not sure what I will ever use it for but it is 'on the shelf'. Thanks, Joe

> John is correct. The mount is, indeed, a Spindler & Hoyer Gottingen, made in Germany. Note that the in is likely 13.7 mm OD... not 1/2" as you might expect. Ealing made compatible stuff. I also think he is correct about what the 'thing' is. > > Measuring the voltage from the unit with the 7081 with aluminium tape over > the front, I get pretty close to 0.0 uV. With the tape removed and the > lights on in the shop, I get about 2 uV. With a small, three AAA battery > powered, LED flashlight illuminating it from close range, I get about 280 > uV. Be careful. The disk and thermopiles are very delicate. Don't even be tempted to even blow on them. > I am not sure what I will ever use it for but it is 'on the shelf'. They are very useful in an optics lab, and are essentially transfer standards between optical power and voltage. -John ================ > > Thanks, > > Joe > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > >

Well, according to my digital caliper, the 'shank' measures 0.498 inches or 12.62 mm. My caliper has not been calibrated. The 'business end' of the unit has a 'slit' shaped opening, about 18.88 mm high and about 2.65 mm wide with a 'V' shaped area in the vertical direction. That 2.65 mm opening looks to be adjustable with two screws that allow the sides to be moved in or out. I have not been (and will not be) adjusting it. There appears to be a glass covering over the thermopiles. Perhaps, in a coming decade, I will find a use for it. Joe ----- Original Message ----- From: "J. Forster" <jfor@quikus.com> To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> Sent: Wednesday, September 21, 2011 10:47 PM Subject: Re: [volt-nuts] Eppley Thermopile >> John is correct. The mount is, indeed, a Spindler & Hoyer Gottingen, > made in Germany. > > Note that the in is likely 13.7 mm OD... not 1/2" as you might expect. > Ealing made compatible stuff. > > I also think he is correct about what the 'thing' is. >> >> Measuring the voltage from the unit with the 7081 with aluminium tape >> over >> the front, I get pretty close to 0.0 uV. With the tape removed and the >> lights on in the shop, I get about 2 uV. With a small, three AAA battery >> powered, LED flashlight illuminating it from close range, I get about 280 >> uV. > > Be careful. The disk and thermopiles are very delicate. Don't even be > tempted to even blow on them. > >> I am not sure what I will ever use it for but it is 'on the shelf'. > > They are very useful in an optics lab, and are essentially transfer > standards between optical power and voltage. > > -John > > ================ >> >> Thanks, >> >> Joe >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> >> > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

If it is like the Funk pattern radiometer it will have a very thin polyethylene film cover to prevent air currents advecting heat to the thermopile. I made a couple of Funk type radiometers using small bismuth teluride (the common cooling devices) peltier elements. You can get a rough calibration by pointing it normal to sunlight on a day with a clear blue sky, close enough to 1000W/m2. (+ - 10%). Cheers, Neville Michie On 22/09/2011, at 2:32 PM, J. L. Trantham wrote: > Well, according to my digital caliper, the 'shank' measures 0.498 > inches or 12.62 mm. > > My caliper has not been calibrated. > > The 'business end' of the unit has a 'slit' shaped opening, about > 18.88 mm high and about 2.65 mm wide with a 'V' shaped area in the > vertical direction. That 2.65 mm opening looks to be adjustable > with two screws that allow the sides to be moved in or out. I have > not been (and will not be) adjusting it. There appears to be a > glass covering over the thermopiles. > > Perhaps, in a coming decade, I will find a use for it. > > Joe > > > ----- Original Message ----- From: "J. Forster" <jfor@quikus.com> > To: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > Sent: Wednesday, September 21, 2011 10:47 PM > Subject: Re: [volt-nuts] Eppley Thermopile > > >>> John is correct. The mount is, indeed, a Spindler & Hoyer >>> Gottingen, >> made in Germany. >> >> Note that the in is likely 13.7 mm OD... not 1/2" as you might >> expect. >> Ealing made compatible stuff. >> >> I also think he is correct about what the 'thing' is. >>> >>> Measuring the voltage from the unit with the 7081 with aluminium >>> tape over >>> the front, I get pretty close to 0.0 uV. With the tape removed >>> and the >>> lights on in the shop, I get about 2 uV. With a small, three AAA >>> battery >>> powered, LED flashlight illuminating it from close range, I get >>> about 280 >>> uV. >> >> Be careful. The disk and thermopiles are very delicate. Don't even be >> tempted to even blow on them. >> >>> I am not sure what I will ever use it for but it is 'on the shelf'. >> >> They are very useful in an optics lab, and are essentially transfer >> standards between optical power and voltage. >> >> -John >> >> ================ >>> >>> Thanks, >>> >>> Joe >>> _______________________________________________ >>> volt-nuts mailing list -- volt-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >>> and follow the instructions there. >>> >>> >> >> >> >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ >> listinfo/volt-nuts >> and follow the instructions there. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ > volt-nuts > and follow the instructions there.