From “A Pointer Volume Spirometer system”, by L.I. Nemerovskii and A.A. Stakhov, Biomedical Engineering, Volume 20, Issue 2, page 54.

“The VS dry spirometer has three identical sections in parallel, each of capacity 2.5 liters, and correspondingly three ranges: 0-2.5, 0-5, and 0-7.5 liter, with three scales.

“The mobile covers for the sections are linked by a carriage running on guides.  The sections are switched manually with a valve mechanism connecting the hose with 1, 2 or 3 sections (then correspondingly 2 or 1 sections communicate with the atmosphere).

“The scales are switched at the same time as the valve mechanism, as they are attached to a drum kinematically coupled to the range switch.”

From “A Pointer Volume Spirometer system”, by L.I. Nemerovskii and A.A. Stakhov, Biomedical Engineering, Volume 20, Issue 2, page 54.

“The measurement unit in a water spirometer is divided by a baffle into two sections equal in volume, so it has two ranges (0-4 and 0-8 liter), and correspondingly two scales with different calibration.  When the 0-8 liter range is set, the patient respires into both sections through a collector and hose with mouthpiece.  On the 0-4 liter range, respires into one of the sections through the hose, while the other communicates with the atmosphere.”

A spirometer manufactured by Metatest in the USSR.  Photo is courtesy of Viktor Lopata, PhD, Senior Researcher of the Bogomolets Physiology Institute, Kiev, Ukraine.

A spirometer manufactured by Metatest in the USSR.  Photo is courtesy of Viktor Lopata, PhD, Senior Researcher of the Bogomolets Physiology Institute, Kiev, Ukraine.

A spirometer manufactured by Metatest in the USSR.  Photo is courtesy of Viktor Lopata, PhD, Senior Researcher of the Bogomolets Physiology Institute, Kiev, Ukraine.

A pediatric spirometer manufactured by Metatest in the USSR.  Photo is courtesy of Viktor Lopata, PhD, Senior Researcher of the Bogomolets Physiology Institute, Kiev, Ukraine.