Ear Simulator for Telephonometry Type 4185 is designed for telephone measurements requiring an IEC 60318–1 coupler. Type 4185 converts the acoustic signal from an earphone into an electrical equivalent that takes into account the response of the human ear. It enables electroacoustic measurements on telephone handsets to be carried out under well‐defined acoustical conditions. Type 4185 fulfils all relevant ITU‐T, IEEE and BS recommendations. Type 4185 consists of an acoustic coupler with built‐in miniature sound source for seal checking, a microphone and a preamplifier. It fits directly into Telephone Test Head Type 4602‐B and can be used with a wide range of Brüel & Kjær telephone test systems. Uses and Features Uses • Measurements on telephone handsets • Earphone calibration • Performance according to ITU‐T Rec. P.57 Type 1 and the IEC 60318–1 standard • Fits Telephone Test Head Type 4602‐B • Incorporates a miniature sound source for automatic seal check • Includes

Description Type 4185 simulates the acoustical impedance of the average human ear, under sealed conditions. The seal between Type 4185 and the handset under test must be completely tight. The quality of this seal can be verified using the miniature sound source located inside the included Acoustic Coupler UA‐1110. This sound source is a small transducer that can be excited with an external signal to produce a sound pressure inside the main cavity. If the seal between the coupler and handset is poor, the sound pressure measured by the microphone will be considerably lower at low frequencies than if the seal is tight....

Compliance with Standards The CE marking is the manufacturer's declaration that the product meets the requirements of the applicable EU directives RCM mark indicates compliance with applicable ACMA technical standards – that is, for telecommunications, radio communications, EMC and EME China RoHS mark indicates compliance with administrative measures on the control of pollution caused by electronic information products according to the Ministry of Information Industries of the People’s Republic of China WEEE mark indicates compliance with the EU WEEE Directive Safety EN/IEC 61000–6–1: Generic standards – Immunity for residential, commercial and light industrial environments...

Specifications – Ear Simulator for Telephonometry Type 4185 General MINIMUM SENSITIVITY –11 dB re 1 Pa/V (at 250 Hz) MAXIMUM INPUT VOLTAGE 10 V ELECTRICAL IMPEDANCE Approximately 1.6  RECOMMENDED FREQUENCY RANGE 100 to 400 Hz Ordering Information OPTIONAL ACCESSORIES Type 4231 Sound Calibrator © Brüel & Kjær. All rights reserved. Brüel & Kjær and all other trademarks, service marks, trade names, logos and product names are the property of Brüel & Kjær or a third‐party company. Brüel & Kjær Sound & Vibration Measurement A/S DK‐2850 Nærum ∙ Denmark ∙ Telephone: +45 77 41 20 00 ∙ Fax: +45 45 80...