Standards on sound and vibration analyzers

Summary form only given, as follows. The American Standards Association has recently issued the "American Standard Method for Specifying the Characteristics of Analyzers Used for the Analysis of Sounds and Vibrations," Z24.15-1955. This standard is limited to the requirements of analyzers for use in analyzing as a function of frequency a complex electrical signal of relatively long duration, such as that obtained from an electroacoustic or electromechanical transducer. The purpose of this standard is to enumerate the important characteristics of such analyzers and to specify the manner in which these characteristics shall be described. Definitions are given for the following terms: Wave Filter, Band-Pass Filter, Nominal Upper and Lower Cutoff Frequencies, Nominal Pass Band Center Frequency, Nominal Bandwidth, Analyzer, Continuously Adjustable Analyzer, Constant-Bandwidth Analyzer, Constant-Percentage-Bandwidth Analyzer (Proportional- Bandwidth Analyzer), Effective Bandwidth for Random Noise. Methods of Specifying Characteristics are listed for the following quantities: Frequency Range and Accuracy, Input Voltage Range, Input Impedance, Source Impedance, Output Voltage, Output Impedance, Load Impedance, Power Requirements, Typeo f Indication, Pass Band Response, Extraneous Influences, Size and Weight, Bandwidth, Transient Response.