handheld Spirometer Palm Size Spiro P is a palm size and measures peak flow (referred to in medical terms as PEF-Peak Expiratory Flow) and "forced expiratory volume" (commonly known as FEV1) in first sencond. it s useful for controlling diseases of the airways such as asthma, C. O. P. D, or chronic bronchitis. Palm size Spirometer with LCD screen Meet ATS (American Thoracic Society) 1994 update standardization. Suitable for hospital or home. Maximum of records is 300 measurements. It can upload to "SpiroSoft" Analyzer software through Bluetooth or USB. work on AAA battery Main Technical Specification: Measuring Parameters: PEF, FEV1 Measuring Methods: Rotating wing wheel Measuring Range: PEF: 30~999L/min FEV1: 0.01~9.99L Measuring Resolution: PEF: 0.2L/s FEV1: 0.01L Measuring Accuracy: PEF: 5% or 0.2L/s, whichever is greater FEV1: 3% or 0.1L, whichever is greater Measuring method Flow £ºTurbine sensor Volume £ºFlow Integration Measuring rang Volume £º0L ~9.99L Flow £º50~900L/min Accuracy Volume £º¡À5% or ¡À0.1L, whichever is greater Flow £º¡À10% or ¡À20L/min, whichever is greater Display £ºSegment liquid crystal display Memory £º300 measur ements with data and time