General Information

Serial #

6761

Part Number

2

Total Parts

3

AKA

N/A

Patents

N/A

General Description

GLASS, METAL & SYNTHETIC COMPONENTS.

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

N/A

Width

N/A

Height

N/A

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Observation equipment

Sub-Category

N/A

Manufacturer

AKA

Unknown

Country

Unknown

State/Province

Unknown

City

Unknown

Context

Country

Canada

State/Province

Ontario

Period

THIS FILTER PRESUMABLY USED C. 1970- 1992.

Canada

THIS FILTER WAS PART OF THE OTTAWA RIVER SOLAR OBSERVATORY INSTALLATION. IT WAS USED ON TELESCOPE 930297, AN INSTRUMENT UNIQUE TO CANADA & THE WORLD. THE 1992 RETIREMENT OF THE ORSO SIGNIFIED THE END OF OPTICAL SOLAR PHYSICS RESEARCH AS CONDUCTED BY CDN GOV'T SCIENTISTS- AN AREA OF STUDY CONCENTRATED IN OTTAWA SINCE 1905.

Function

USED ON SOLAR TELESCOPE AS AID IN PHOTOGRAPHY OF SPECIFIC AREA OR SPECTRUM OF PHOTOSPHERE. USED ALSO TO CONTROL PATH OF LIGHT TO MONOCHROMATOR..2 &.3 USED TO REGULATE TEMPERATURE OF FILTER.

Technical

THIS FILTER, HAVING A 1A (ANGSTROM) TO 0.5A BANDPASS, WAS PART OF THE OPTICAL ARRANGEMENT USED TO PERFORM AN H-ALPHA PATROL OF ENTIRE DISC AND OF LIMB FEATURES OF CHROMOSPHERIC MATERIAL. PHOTOGRAPHY OF THE WIDE BAND OF THE CONTINUUM WAS SIMULTANEOUS WITH THAT OF AN AREA -8+ A FROM THE H-ALPHA LINE CENTRE. (REF.2 P.4). THERMOMAT CONTROLLED TEMP. OF FILTER, A CRITICAL FACTOR

Area Notes

Unknown

Details

Markings

.1 Mfr's plate screwed to filter casing reads " B. Halle Nachf./ Berlin-Steglitz./ Filter No 85 ". Purple decal applied to right of plate reads " HERZBERG INSTITUTE/ OF ASTROPHYSICS/ H1A- 00045/ ASTROMONY SECTION ". White decal applied below reads " Property of/ Propriete du/ NRCC/CNRC/061714 ". All controls labelled./ PT wooden box bears red dymo tape label reading " HALLE H. ALPHA FILTER "/.2 Thermomat bears' mfr's plate marked " Thermomat/ Nr. 6761/ 110V~ 90 W ". Green dymo label on front panel reads " DO NOT TOUCH METER/ CONTACT MAY CAUSE STATIC ERROR ". Red dymo label, beside, reads " THERMOSTAT/ HALLE H. ALPHA FILTER "./ .3 Green dymo label reads " HALLE FILTER/ CONTROLLER". Red dymo label reads " LEAVE AT 6.48 "

Missing

NONE.

Finish

OUTER CASING/MOUNTING ASSEMBLY HAS FLAT BLACK FINISH; FITTED WITH WHITE SYNTHETIC ADJUSTMENT DIAL. MOST OF LENS CASING EXTERIOR HAS DIMPLE-TEXTURED MEDIUM GREY FINISH; DARK-GREY AND BLACK TRIM. TEMPERATURE & FINE ADJUSTMENT SCALES, AND LEVEL PROTECTED WITHIN GLASS ENCLOSED HOUSING.

Decoration

N/A