sound level meter
Date1960-1970
Inventory Number1999-1-0055
ClassificationSound level meter
Subject
Manufacturer
General Radio Company
1915-present
Cultural Region
Place of Origin
Dimensionsas pictured: 30.6 × 19.5 × 24 cm (12 1/16 × 7 11/16 × 9 7/16 in.)
Material
Accessoriesoperation manual
DescriptionBlack rectangular instrument with a silver, metal microphone which can fold down on the top. Several dials and meter in decibels on the top to adjust sound level.
The "JMH" scratched to the top right hand face are the donor's initials.
A technical manual, "Operating Instructions Type 1551-c Sound-Level meter" come with it.
The patent was actually given not for the instrument per se, but for the calibration apparatus embedded in it. Such apparatus was used to calibrate the sensitivity of electronic amplifying systems. Though adaptable to any kind of amplifier system, it was particularly advantageous, the patent says, in connection with sound-level meter amplifying equipment, like this one here.
The "JMH" scratched to the top right hand face are the donor's initials.
A technical manual, "Operating Instructions Type 1551-c Sound-Level meter" come with it.
The patent was actually given not for the instrument per se, but for the calibration apparatus embedded in it. Such apparatus was used to calibrate the sensitivity of electronic amplifying systems. Though adaptable to any kind of amplifier system, it was particularly advantageous, the patent says, in connection with sound-level meter amplifying equipment, like this one here.
Signedon top: GENERAL RADIO COMPANY
Curatorial RemarksThe city mentioned is Concord, MA, not Cambridge.
FunctionBasic instrument of General Radio sound measuring system. It indicates the sound pressure level of its microphone in terms of a standard reference level. Can also be used as a highly sensitive AC voltmeter.
ProvenanceProfessor John Michael Harrison, Department of Psychology, Boston University, pre-1998; gift to CHSI, 1999.
Historical AttributesS.S. Stevens loaned to the donor an earlier model of sound level meters in the 1950s. This meter was the standard in the industrial and research fields.
General Radio Company
Date: 1920-1930
Object number: RS0487
Triplett
Date: 1930-1950
Accessories: plain cardboard box fitted for this meter; small sealed envelope of hardware
Object number: WJ1276
Westinghouse Electric & Manufacturing Company
Date: 1890-1930
Object number: RS0517
Clapp-Eastham Company
Date: 1922
Accessories: Manual included.
Object number: RS0061
Harvard Cyclotron Laboratory
Date: 1947-2002
Object number: 2003-1-0291
Grason-Stadler Company
Date: 1960-1970
Accessories: extra screws and washers
Object number: 1999-1-0057
Ballantine Laboratories, Inc.
Date: copyright 1953
Accessories: Instruction booklet, see 1998-1-1372b
Object number: 1998-1-1372a
Date: 1910-1940
Accessories: Diagram
Object number: RS0515
