From: http://www.radiomuseum.org. Manufactured by H. Wohlgroth & Co., Zurich, Switzerland. Probably from around 1960. Wohlgroth & Co. were noted as manufacturers of gas meters so this spirometer may be of that type.
From: http://www.radiomuseum.org. Manufactured by H. Wohlgroth & Co., Zurich, Switzerland. Probably from around 1960. Wohlgroth & Co. were noted as manufacturers of gas meters so this spirometer may be of that type.
