Leeds & Northrup Company, hydrogen ion concentration instrument, 1921, 1936, 1937
name: label: Collection Creator
content: Instrument Society of America
setName: label: See more items in
content: Instrument Society of America Collection
label: See more items in
content: Instrument Society of America Collection / Series 3: Trade Literature
container: label: Container
content: Box 68, Folder 5
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
objectType: label: Type
content: Archival materials