Measurement microphone 4939

externally-polarizedwith built-in TEDS preamplifierwith built-in preamplifier

Overview
Family 4939 is a 1/4" free-field microphone set with external polarization and stainless steel diaphragm and grille, developed for acoustic measurements in extreme industrial environments. Units can be supplied as sealed microphone + preamplifier assemblies with unique type and serial identification and optional TEDS.

Key features

• 1/4" free-field microphone set, externally polarized
• Stainless steel diaphragm and grille for corrosive or harsh environments
• Sensitivity variants available (typ. 3.5 mV/Pa and 4 mV/Pa)
• Designed for acoustic testing at elevated temperatures (marketing information indicates up to 150°C)
• Delivered with microphone set components and connector variants per configuration

Applications

• Free-field acoustic measurements
• Industrial sound testing in high-temperature or corrosive environments
• Production and end-of-line acoustic quality control where rugged sensors are required

Variants and usage notes

• Requires external preamplifier for operation; recommended preamplifier when combined: type 2669-L
• Available sensitivity variants and set configurations (see model suffixes)
• Units can include TEDS for automatic identification (type, serial, sensitivity)

Technical specifications

• Product family / model: Family 4939 (TYPE 4939)
• Product type: Free-field microphone set (IEC 61094 reference)
• Polarization: externally polarized (classic)
• Sensitivities: typically 3.5 mV/Pa and 4 mV/Pa (model dependent)
• Frequency range: approx. 4 Hz – 100 kHz
• Dynamic range (typ.): low ≈35 dB, high ≈164 dB
• Diameter: 1/4"
• Venting: side venting for pressure compensation
• Output: passive (requires external preamplifier)
• Materials: stainless steel diaphragm and grille
• Operating temperatures: marketing information indicates reliable testing up to 150°C; specification table lists a maximum operational temperature of 80°C (see manufacturer documentation for applicable limits)
• Assembly and traceability: units may be assembled in cleanroom, sealed, with unique type and serial number; TEDS supported