1/2-inch Microphone/ Preamplifier
MI Series
There are MI-1271, 1/2-inch back electrets-type microphone which has improved the environmental stability against temperature and humidity, MI-1235 which emphasizes on a wide frequency range and MI-1433 which realizes a similar environmental resistance at a low price. MI series microphone is used in combination with the preamplifier and the microphone. Since microphone and preamplifier are not built-in type, installation costs can be reduced in the event of a fault.
MI-1271
MI-1271 is 1/2-inch back electrets type precision microphone which conforms to IEC 61094-4 Type WS2F(Measurement microphones- Part 4: Specifications for working standard microphones). By adapting laser welding fixation of titanium vibrating membrane, it realizes long-term stability. In addition, wide temperature/humidity range (-30 ℃ to +80℃/ 0 to
90% RH) and wide frequency range (1 Hz to 20 kHz) enable to meet wide variety of applications, such as measurement of environmental noise in high-temperature and humidity environment, measurement of sound with very low frequency (up to 20 Hz), and sound measurement during cold start tests of automobiles.
MI-1235
MI-1235 is best to be used as measurement and analysis for environmental noise, architectural acoustics, and radiated sound from electrical/mechanical instruments. And it has a wide frequency range of 10 Hz to 20 kHz.
It is precision microphone used with the MI-3111 microphone preamplifier.
MI-1433
MI-1433 is excellent for environmental noise measurement with frequency range of 20 Hz to 8 kHz. It is general microphone with low cost used with the MI-3111 microphone preamplifier.
MI-1271/3170 Product video (YouTube)
System Configuration
Each product illustration in the below configuration is linked to its own page.
Specifications
Model name |
MI-1271 | MI-1235 | MI-1433 |
|---|---|---|---|
| Response type | Free sound field | ||
| Positive voltage | 0 V | ||
| Sensitivity (1 kHz) | -26 dB±1.5 dB re. 1 V/Pa 50 mV/Pa (1 kHz) |
-29 dB ±3 dB re. 1 V/Pa 36 mV/Pa (1 kHz) |
|
| Capacitance (1 kHz) | 12 pF (Representative value) |
13 pF (Representative value) |
|
| Frequency range (1 kHz at standard) |
1 Hz to 20 kHz (±2 dB) |
10 Hz to 20 kHz (+1.5 dB,-5 dB) 10 Hz to 10 kHz (+1.5 dB,-2 dB) |
20 Hz to 8 kHz (±2 dB) |
| Effective load volume | 359 mm3 | 260 mm3 | 239 mm3 |
| Maximum sound pressure level
(Total harmonic distortion 3 %)
|
135 dB (when using MI-3170) |
135 dB(when using MI-3111) 141 dB(when using MI-3170) |
|
Self-noise level (A-weighting) |
14.0 dB (representative value) |
19.0 dB (representative value) (when using MI-3111) |
|
| Operating temperature range | -30 to +80 ℃ | -10 to +50 ℃ | |
| Operating relative humidity range | 0 to 90 % (with no condensation) |
20 to 90 % (with no condensation) |
|
| Storage temperature range | -40 to +70 ℃ | -20 to +60 ℃ | |
| Storage relative humidity range | 0 to 90 % (with no condensation) |
10 to 90 % (with no condensation) |
|
| Weight | Approx. 6 g | ||
| Outer dimension | φ13.2 mm × 16.9 mm | φ13.2 mm × 13.7 mm | φ13.2 mm × 13.5 mm |
MI-3170
MI-3170 is a preamplifier for 1/2-inch back-electret type condenser microphone, it can be used in combination with MI-1271 microphone. Adopting the CCLD method and BNC connector, various types of CCLD accepted amplifier, analyzer and data recorder can be connected directly. It covers the measurement range of ultra low frequency of 1Hz and can be used in wide operating temperature range (-30 to +80 °C) .
MI-3111
MI-3111 is a preamplifier for 1/2-inch back-electret type condenser microphone. It is CCLD and BNC connector type.
It is a general preamplifier used with the MI-1235/MI-1433 microphone.
Specification
| Model name | MI-3170 | MI-3111 |
|---|---|---|
| Applicable microphone | MI-1271/1235/1433 (Discontinued)MI-1233/1234/1431/1432 |
MI-1235/1433 (Discontinued)MI-1233/1234/1431/1432 |
| Insertion loss | 0.15 dB (at 1 kHz)(representative value) | 1.0 dB(representative value) |
| Frequency range | 10 Hz to 40 kHz (+0.1 dB,-0.2 dB,1 kHz as reference) (+0.1 dB,-1.5 dB,10 Hz as reference) |
10 Hz to 20 kHz (±1.0 dB,1 kHz as reference) 20 Hz to 20 kHz (±0.6 dB,1 kHz as reference) |
| Input impedance | 40 GΩ | 5 GΩ±15% |
Self-noise (effective voltage) |
3.3 µV or less | 5.0 µV or less |
| Total harmonic distortion |
0.0316 % or less (Input frequency 1 kHz, Input effective voltage 1 V) 0.1 %(-60 dB) or less (Input frequency 20 kHz, Input effective voltage 1 V) |
1 % or less (Input frequency 1 kHz, Input effective voltage 3.15 V) |
| DC bias voltage | 12 V ± 2 V | 8 V ± 1 V |
| Maximum output voltage | ±8 V (Peak) (driving power 24 VDC, 4mA)
Sound pressure conversion135 dB (Sensitivity 50 mV/Pa when using microphone) |
±5.6 V (peak) (driving power 24 VDC, 4mA)
Sound pressure conversion 135 dB (Sensitivity 35 mV/Pa when using microphone) |
| Operating temperature range | -30 to +80 ℃ | -10 to +50 ℃ |
| Operating relative humidity range | 0 to 90 %(not including microphone) | 30 to 90 %(not including microphone) |
| Storage temperature range | -40 to +70 ℃ | -20 to +60 ℃ |
| Storage relative | 0 to 90 %(not including microphone) | 10 to 90 %(not including microphone) |
| Power supply | CCLD 2 to 4.5 mA,DC 18 to 26 V |
CCLD 0.5 to 5 mA,DC 15to25 V |
| Applicable connector | C02(BNC) | |
| Weight | Approx. 35 g (not including microphone) | Approx.25 g(not including microphone) |
| Outer dimension | φ12.7 mm × 80.5 mm | φ12.7 mm × 63.5 mm |
| Accessory | Protection cap for input connector×1
|
Protection cap for input connector×1 Microphone holder (MI-0301)×1 Instruction manual x1 |
| Extension cable | MX-1000 series (recommended), MX-2000 series | MX-2000 series (recommended) |
Connection cable (both terminals are BNC connector)
| Model name | Outer dimension | Length | Operating temperature range |
|---|---|---|---|
| MX-1001 | Signal cable for low/ high temperature |
1.5 m | -30 to +80 ℃ |
| MX-1005 | 5 m | ||
| MX-1020 | 20 m | ||
| MX-2001 |  |
1.5 m | 0 to +60 ℃ |
| MX-2005 | 5 m | ||
| MX-2020 | 20 m |
Revised:2022/09/29
