Designed to measure the sound pressure in the sound field, compensating for the influence of the presence of the microphone in the sound field. The microphone measures the sound pressure as it existed before the microphone was introduced in the sound field, i.e. free-field conditions.
Designed to measure the sound pressure in the sound field, compensating for the influence of the presence of the microphone in the sound field. In effect, the microphone measures the sound pressure as it existed before the microphone was introduced in the sound field, i.e. free-field conditions. The free field microphone should be pointed towards the sound source at a 0° angle of incidence.
These free-field microphones are designed to measure sound as it exists in an open, unobstructed environment — that is, a free field where there are no nearby reflective surfaces that could affect the sound. These microphones are calibrated to account for the way sound waves behave when they directly strike the microphone diaphragm without any interference from surrounding objects.
Frequency response: (18 pF/small signal): 20 Hz ¬– 20 kHz: ±0,1 dB
Gain: Typ -0.1 dB (-0.2 with 20 pF)
Input impedance: 10 GΩ, 1.4 pF
Output impedance: 50 ohm typical
Noise (20 pF dummy mic.):
i. A-weighted < 2,2μV (typ 1,8μV)
ii. Lin (20 Hz – 20 kHz) <6 μV (typ 3,8 μV)
Power Supply:
i. Single: 28 V (1mA) to 120 V (2.8mA)
ii. Dual: ±14 V(1 mA) to ± 60 V (2.8 mA)
iii. Maximum signal output voltage (peak): ±10 to ±50 V (dep. on supply)
Temperature: -25°C to +70°C (operation)
Relative humidity: 0 – 90%
Length: 83 mm
Body Diameter: 12.7 mm
Ring Diameter: 14 mm
Weight: 36 g
EC classification: As for sound level meter Nor140.
Cartridge Size: 1/2″
Design: IEC 61094-4 Type WS2F
Frequency response: Free-field type
Sensitivity level (nominal value):
−26 dB (re. 1 V/Pa at 1 kHz) / 50 mV/Pa
Cartridge Capacitance (nominal value): 13 pF
Frequency range: 10 Hz to 20 kHz
Maximum input sound pressure level:
148 dBrms @ 3% distortion
Inherent noise (A-weighted equivalent sound pressure level): <16 dB
Temperature sensitivity (ref to 23°C @ 1 kHz):
<±0.35dB (−10°C to +50°C)
<±0.5dB (−20°C to +60°C)
Humidity (ref 23°C , 50% RH): < ±0.14 dB max. (at 1 kHz, no condensation, 90% RH or less)
Atmospheric pressure sensitivity (ref 101.325 kPa @ 250 Hz):
<±0.4 dB from 85 kPa to 108 kPa
<±0.9 dB from 65 kPa to 85 kPa
Ambient temperature/humidity range for operation:
20°C to +60°C, 90% RH (no condensation)
Ambient temperature range for storage:
−20°C to +60°C
Dimensions (with protection grid):
13.2 mm dia. × 14.3 mm height
Preamplifier threads: 11.7 mm 60 UNS
Weight: 4.7 g
