Tidal volume was monitored with a heated Fleisch pneumotachograph that was mounted downstream of a Hans Rudolph two-way high velocity valve. Exhaled air was collected in plastic and neoprene bags, the volume subsequently measured with precision gas meters. Gas concentrations were measured with a gas chromatograph. The bicycle eergometer used friction resistance to maintain and steady workload and the subject pedealed to a metronome. Taken from the “The inhalation of the photochemical smog compound peroxyacetyl nitrate” by Leon E. Smith EdD in AJPH volume 55, no 9, Sept 1965, page 1460.
Intended primarily for spirometry, some versions came with a helium analyzer and could be used to measure lung volumes. Taken from: http://bid.mclemoreauction.com/cgi-bin/mnarclist.cgi?mclemore/20081028/category/LAB-AND-MEDICAL-EQUIPMENT
Photograph is courtesy of Darren Hoffberger, a collector of antique spirometers. It is a bellows spirometer with its own carrying case. The volume is read off the brass scale at the back. Manufactured by Jules Richard, 25 Rue Melingue, Paris. Exact date unknown but most likely pre-1900.
From: http://digidownload.libero.it/medlavparma/spiro/storia_spiro3.pdf
Breve Storia illustrata della spirometria by Dott. Andrea Innocenti
The diverse, quirky and mostly forgotten history of Pulmonary Function testing