General Information

Serial #

1206

Part Number

1

Total Parts

2

AKA

N/A

Patents

N/A

General Description

METAL, GLASS & SYNTHETIC COMPONENTS.

Dimensions

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

Length

112.0 cm

Width

66.0 cm

Height

138.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Research

Sub-Category

N/A

Manufacturer

AKA

JOYCE

Country

England

State/Province

Unknown

City

Gateshead-on-Tyne

Context

Country

Canada

State/Province

Ontario

Period

THIS INSTRUMENT PRESUMABLY USED C. 1960S+. THIS TYPE MFD 1950S-1970S, AND STILL USED IN 1990S +

Canada

PART OF A COLLECTION OF PHYSICS LABORATORY AND CLASSROOM DEMONSTRATION APPARATUS FROM MCMASTER UNIVERSITY. FOUNDED IN 1887 MCMASTER WAS ORIGINALLY A BAPTIST INSTITUTION, AND WAS LOCATED IN TORONTO. IN 1930 THE UNIVERSITY AND ITS STUDENT POPULATION OF 500 WAS MOVED TO HAMILTON, ONT. ( REF. 1)

Function

TO MEASURE THE PHOTOGRAPHIC DENSITY OF SPECTRAL LINES ON A NEGATIVE WHICH ARE TOO FAINT TO BE SEEN WITH THE NAKED EYE.

Technical

JOYCE LOEBL, BASED IN THE NORTH EAST OF ENGLAND, BUILT 1000S OF MICRODENSITOMETERS DURING THE 1950S- 1970S, AND THEY WERE SOLD AND USED WORLDWIDE. MICRODENSITOMETERS WERE THE LAST PRE-COMPUTER DEVICES FOR SPECTRAL ANALYSIS: THEY WERE REPLACED IN THE 1970S BY SCANNING DEVICES CONTROLLED BY A PDP COMPUTER. THE MICRODENSITOMETER IS CONSIDERED BY MANY TO BE THE MOST PRECISE INSTRUMENT FOR THE MEASUREMENT OF GREY SCALE ON PHOTOGRAPHIC EMULSIONS. (REF. 2)

Area Notes

Unknown

Details

Markings

"JOYCE/ LOEBL" plate appears on control panel; all controls, etc. labelled. Handwritten labels also on control panel reads " TURN SUPPLY/ ON FIRST/ leave 10 min./ (THEN LAMP)/ TURN LAMP/ OFF FIRST/ (THEN SUPPLY) ". Plate on left side panel reads " DOUBLE-BEAM RECORDING/ MICRODENSITOMETER/ MK III CS SERIAL NO.1206/ MADE BY/ JOYCE, LOEBL & CO.LTD./ ELECTRON HOUSE,/ PRINCESWAY, TEAM VALLEY,/ GATESHEAD-ON-TYNE, II./ ENGLAND ". Orange decal, beside, reads " ontario hydro/ electrical/ approval/ by special inspection series A ". Small plate on instrument bed reads " THIS INSTRUMENT IS MADE UNDER/ LICENCE FROM N.R.D.C AND COVERED/ BY PATENT NO. 15764/54 ". Optical lens suspended over bed marked " X10/.17 " and "X10 BECK ". Optical lens recessed in bed marked " VICKERS 3/0.1 " and " S3917 ". Paper label taped to side of microdensitometer reads " STORAGE NO.:------- DATE: Oct. 28/81 / ITEM: Joyce Loeble [sic] & Co. microdensitometer/ S/N: 1206 MODEL: Mk. III CS/ STATUS storage/ REPAIR $ ? / RESEARCHER: from 3N3/ OTHER: ---------- ". Inventory decal on instrument reads " MCMASTER/ HEALTH SCIENCES/ OP5-301-723-FHS/ [barcode]/ *A005868* ".

Missing

UNKNOWN: THIS MACHINE MAY HAVE BEEN MODIFIED.

Finish

SMOOTH GREEN-GREY ENAMEL FINISH; SOME BLACK AND SILVER METAL COMPONENTS AND FITTINGS

Decoration

N/A