General Information

Serial #

44011

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

Metal casings, controls and parts/ Synthetic meter casing, controls, carrying strap, feet, parts

Dimensions

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

Length

53.5 cm

Width

50.0 cm

Height

64.2 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Communications

Category

Service-test equipment

Sub-Category

N/A

Manufacturer

AKA

Keithley

Country

United States of America

State/Province

Ohio

City

Cleveland

Context

Country

Canada

State/Province

Ontario

Period

mid 1960s +

Canada

An instrument used at the David Dunlap Observatory at the University of Toronto, one of Canada's most important astronomical observatories. The David Dunlap Observatory opened in 1935 as the result of a bequest from the wife of David Dunlap. The telescope was a 74 inch (188 cm) reflector built by Grubb Parsons of Newcastle-upon-Tyne in England. The 74 inch was then the largest telescope in Canada (surpassing the 72 inch telescope of the Dominion Astrophysical Observatory in Victoria) and became the second largest in the world after the 100 inch Hooker Telescope of the Mt. Wilson Observatory outside Los Angeles. DDO's reputation grew and following WWII, it began to graduate most of the astronomers produced in Canada with University of Western Ontario far behind. Beginning in the 1960s a number of other astronomy departments were created but UofT/DDO held its place, a position it probably still holds. The DDO had a good technical staff which gave them an advantage and, with most of the 1940s to early 1970s top astronomers coming from UofT, grants from NRC and then ENSERC were almost guaranteed and allowed UofT's top astronomers -- Hogg, van den Berg, Fernie, Bolton, Kamper, Martin, etc. to acquire or build some of the best equipment available in university observatories. For optical observatories, only the DAO had technical staff and budgets that surpassed those of DDO. In 2007, citing increasing light pollution, the University of Toronto announced plans to sell the Observatory property. In June 2008, it was sold to Corsica Development Inc., a subsidiary of Metrus Development Inc. and the Observatory was closed. In 2009 the Observatory buildings and 80% of the site were designated a cultural heritage landscape. Also in 2009 Corsica and the Royal Astronomical Society of Canada, Toronto Centre announced an agreement allowing the RASC to provide public education and outreach programs at the observatory, and to operate the 188 cm telescope.

Function

Generally, an instrument for measuring low current, an ammeter with a scale which indicates current in picoamperes. This one was used with the photoelectric photometers of a telescope at an astronomical observatory.

Technical

One of a group of instruments used in the DDO Electronic Shop for calibration and testing of the Observatory's observational instruments. This one was used with photoelectric photometers at the telescope. It has a Keithley Input Head model 4160. Note this is identical to the one used with the St.Mary's University / Fernie photometer which was acquired by SMU in 1972. Range: 10(-5) to 10(-12) amps (picoamp range). This type of picoammeter is useful for high-speed measurements of low-level currents generated by high-impedance sources such as photo-multipliers, high-speed mass spectrometers, ion chambers, ans flame and beta-ray ionization detectors. Other applications include transient current measurements, noise studies and flash filament testing. This example is identical to the Keithley model 417 picoammeter (2008.0208) except that the 417 provides a suppression current at the input up to 1000 times full scale on most ranges (Ref. 2).

Area Notes

Unknown

Details

Markings

Picoammeter: Black lettering on picoammeter front reads '416 HIGH SPEED PICOAMMETER' and 'KEITHLEY INSTRUMENTS INC. CLEVELAND OHIO MADE IN U.S.A.'; Black lettering on input head casing reads '4160 INPUT HEAD'; Label on back reads 'K [logo] 44011/ KEITHLEY INSTRUMENTS/ INC. CLEVELAND OHIO USA'; Black lettering on ammeter face reads 'KEITHLEY INSTRUMENTS'; Black lettering for control functions on front and back; Blue pressure printed labels read '74AB' on picoammeter and '74PB' on input head/ Power supply: Plate on front reads 'FLUKE [logo] 07013'; Black lettering on front reads '412B HIGH VOLTAGE POWER SUPPLY'; Black lettering on voltmeter dial face reads 'KILOVOLT/ FLUKE [logo]'/ Transformer: Lettering on plate reads 'SOLA CHGO. U.S.A./ CONSTANT VOLTAGE TRANSFORMER/ U.S. PATS 2,582,291 - 2, 694,117/ 547,029 AND PATS. PEND./ CAT NO. 20-13-60 J845 TYPE NO. CV-1/ PRI V. 950130 CYC. 60 PH. 1/ SEC V. 110 AMP. 508 P.F.% 100 va. 60/ Transformer: Lettering on plate reads 'JEFFERSON/ TRANSFORMER/ CAT. NO. 231 102/ V.A. 50/ PRI V. 110 CYC. 25' and 'CANADIAN JEFFERSON ELECTRIC CO./ LIMITED/ TORONTO CANADA'

Missing

Unknown

Finish

Rack: glossy grey painted exterior/ Picoammeter: glossy grey painted casing front/ Metallic grey casing sides, top, back, underside; Black meter casing with white face; Black painted and brushed metal controls with colourless synthetic dials; Black and grey synthetic cord coverings and parts; Gold coloured connector/ Power supply: Metallic grey casing front/ Black synthetic voltmeter dial casing with colourless transparent cover, white face; Black synthetic controls; Metallic grey switches; Red and white lamps; Metallic grey parts/ Transformer: Grey painted casing; black cord covering/ Transformer: Black painted casing

Decoration

Black 'K' logo on input head/ Red 'K' logo on ammeter face/ Vertical black stripe painted on each side of power supply casing front