ONO SOKKI - 1/4-inch Measurement Microphone and Preamplifier

1/4-inch Measurement Microphone

1/4-inch Measurement Microphone and
Preamplifier
MI-1531/MI-3140

The 1/4-inch diameter condenser microphone MI-1531 with its preamplifier MI-3140 enable to measure the high frequency band more than 20kHz which it is impossible by using the 1/2-inch microphone. Amplifier is not required in use as it is a back electret-type condenser microphone, which differs from a bias-type microphone. And also, the MI-1531 achieves a measurement at Max. 168 dB as a performance of a microphone itself.

MI-1531

Photo (MI-1531 Measurement Microphone)

Adopting back-electret type

The MI-1531 does not need bias-type microphone preamplifier because it is combined with a constant current type of preamplifier. It can be directly connected to an amplifier or a data processing unit which have a BNC (C02 type) connector. (Constant current power supply at the range from 2mA to 20mA is required at the equipment.)

Achieving high-frequency measurement more than 20kHz

The MI-1531 enables to measure the high frequency band more than 20kHz which it is impossible by using the 1/2-inch diameter microphone.

10 Hz to 40 kHz
(Frequency characteristic: ±1dB without protection-grid) 10 Hz to 100 kHz
(Frequency characteristic: +2dB,-4dB without protection-grid)
10 Hz to 20 kHz
(Frequency characteristic: -4dB with protection-grid)

Able to measure the high sound pressure level

The MI-1531 achieves a measurement at Max. 168dB as a performance of a microphone itself and 157dB in combination with the MI-3140 preamplifier

MI-3140

Photo (MI-3140 Preamplifier)

Connection Diagram

Each product in the analyzer section in the below configuration is linked to its HTML page.

Illustration (1/4-inch Microphone Connection Diagram)

Specifications

MI-1531 1/4-inch Measurement Microphone

Frequency Range	10 Hz to 100 kHz
Response Type	Sound Field
Sensitivity	－48 ± 3 dB（0 dB = 1 V/Pa）
Capacitance	7 pF
Max. Sound Pressure Level	157dB (when used with MI-3140 preamplifier)
Intrinsic Noise Level	30 dB or less（A-weighting）
Operating Temperature Range	-10 to 50°C
Operating Humidity Range	0 to 90%RH (with no condensation)
Temperature Characteristics	0.01dB/°C or less
Storage Temperature Range	-40 to 150°C
Storage Humidity Range	0 to 90%RH
Outer Dimensions	φ 6.9 × 10.5 mm
Weight	Approx. 1.5 g

MI-3140 Preamplifier

Applicable Microphone	MI-1531
Frequency Range	10 Hz to 100 kHz
Gain	-0.25dB (Typical)
Input Impedance	Approx. 20 GΩ
Intrinsic Noise	6 μVrms or less (FLAT)
Distortion	3% or less
Operating Temperature Range	-30 to 60°C
Operating Humidity Range	0 to 90%RH
Max Output	±8 V or less
Power Supply Voltage	15 to 25 V, 2 to 20 mA
Cable	sold separately (NP-0130 series)
Outer Dimensions	φ 6.35 × 44 mm
Weight	Approx. 5.5 g
Connection cable	NP-0130 series
Accessories	SC-0313 conversion adopter 1/2 to 1/4 for calibration
Option	NP-0021 BNC (C02 Type) conversion adapter NP-0020 connector (for NP-0130 series)

Cable

Model	Length	Outer dimension
NP-0131	1.5m
NP-0132	3m
NP-0133	5m
NP-0134	10m

Revised: 2011/10/03