The MI series are back electrets and sound field type measurement microphones.
The lineup is as follows:
- Measurement Microphone;
- Microphone Preamplifier; and
- TEDS Microphone
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 °C to +80°C/ 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 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 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.
The MI-1531 is the 1/4-inch diameter microphone.
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.
| Model name | MI-1271 | MI-1235 | MI-1433 | MI-1531 |
|---|---|---|---|---|
| Size | 1/2-inch | 1/4-inch | ||
| Polarization voltage | 0 V | |||
| Sensitivity | -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) |
-48 ± 3 dB re. 1 V/Pa 4 mV/Pa (250 Hz) |
|
| Frequency range | 1 Hz to 20 kHz | 10 Hz to 20 kHz | 20 Hz to 8 kHz | 10 Hz to 100 kHz (without protection grid) 10 Hz to 20 kHz (with protection grid) |
| Maximum sound pressure | 135 dB (when using the MI-3170) | 135 dB (when using the MI-3111) | 157 dB (when using the MI-3140) | |
| Self-noise level (A-weighting) |
14.0 dB (Typ. value, when using MI-3170) |
19.0 dB (Typ. value, when using MI-3111) |
30 dB (Typ. value, when using MI-3140) |
|
| Operating temperature range | -30 to +80 °C | -10 to +50 °C | -30 to +60 °C | |
| Operating humidity range | 0 to 90 % (with no condensation) | 20 to 90 % (with no condensation) | 0 to 90 % (with no condensation) | |
| Storage temperature range | -40 to +70 °C | -20 to +60 °C | -30 to +80 °C | |
| Storage humidity range | 0 to 90 % (with no condensation) | 10 to 90 % (with no condensation) | 0 to 90 % (with no condensation) | |
| Outer dimensions | φ13.2 mm × 16.9 mm | φ13.2 mm × 13.7 mm | φ13.2 mm × 13.5 mm | φ6.9 mm × 10.5 mm |
| weight | Approx.6 g | Approx. 1.5 g | ||
| Applicable preamplifier | MI-3170 | MI-3111 | MI-3140 | |
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 °C to 80 °C).
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.
The MI-3140 is a preamplifier for 1/4-inch back-electret type condenser microphone.
It is CCLD and 10-32 UNF connector type. Ideal for measurement in a limited space.
It is a general preamplifier used in combination with MI-1531 microphone.
| Model name | MI-3170 | MI-3111 | MI-3140 |
|---|---|---|---|
| Size | 1/2-inch | 1/4-inch | |
| Applicable microphone | MI-1271/1235/1433 | MI-1235/1433 | MI-1531 |
| Attenuation (typical) | 0.15 dB | 1.0 dB | 0.25 dB |
| Frequency range | 10 Hz to 40 kHz (+0.1 dB,-0.2 dB,1 kHz as reference) 1 Hz to 40 kHz (+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) |
10 Hz to 100 kHz (+0.5 dB as reference) |
| Self-noise (effective value voltage, A-weighting) |
3.3 μV or less | 5.0 μV or less | 2.5 μV or less (20 Hz to 20 kHz) |
| Max. Output voltage | ±8 V (peak) Sound pressure conversion 135 dB (when using the MI-1271) |
±5.6 V (peak) Sound pressure conversion 135 dB (when using the MI-1235 / 1433) |
±8 V (peak) Sound pressure conversion 157 dB (when using the MI-1531) |
| Operating temperature range | -30 to +80 °C | -10 to +50 °C | -30 to +60 °C |
| Operating humidity range | 0 to 90 % (with no condensation) | 30 to 90 % (with no condensation) | 0 to 90 % (with no condensation) |
| Storage temperature range | -40 to +70 °C | -20 to +60 °C | -30 to +80 °C |
| Storage humidity range | 0 to 90 % (with no condensation) | 10 to 90 % (with no condensation) | 0 to 95 % (with no condensation) |
| Power supply | CCLD 2 to 4.5 mA,DC 18 to 26 V | CCLD 0.5 to 5 mA,DC 15 to 25 V | CCLD 2 to 20 mA,DC 18 to 25 V |
| Applicable connector | C02(BNC) | 10-32 UNF | |
| Outer dimensions | φ12.7 mm × 80.5 mm | φ12.7 mm × 63.5 mm | φ6.35 mm × 44 mm |
| Weight | Approx. 35 g (not including microphone) | Approx. 25 g (not including microphone) | Approx. 5.5 g (not including microphone) |
| Cable | MX-1000 series (recommended),MX-2000 series | MX-2000 series (recommended) | NP-0130 series (recommended) |
| Accessory | Protection cap for input connector× 1 MI-0301 (microphone holder for mounting tripod)× 1 Instruction manual × 1 |
Protection cap for input connector× 1 SC-0313 conversion adapter (1/2 to 1/4-inch) × 1 Instruction manual × 1 |
|
The MI-1271M12 TEDS Microphone can be used by directly connecting to a device equipped with CCLD (Constant Current Line Drive) with BNC cable.
Also, when connected to TEDS applicable device, information such as sensitivity is automatically loaded without troublesome calibration. As a result, reliable measurement and time reduction are possible.
| MI-1271M12 | Specification | |
|---|---|---|
| Diameter, response type,polarization voltage | 1/2-inch, free sound field, 0 V | |
| Sensitivity | -26 .0 ± 1.5 dB re.1 V/Pa (50 mV/Pa) | |
| Frequency range | 1 Hz to 20 kHz (± 2 dB) | |
| Maximum sound pressure level (250 Hz, 3% distortion) |
135 dB | |
| Cartridge thermal noise (A-weighting) |
14.0 dB (re.) | |
| Pressure coefficient(250 Hz) | -0.013 dB/kPa | |
| Temperature coefficient(250 Hz) | +0.005 dB/K | |
| Humidity coefficient(250 Hz) | -0.0004 dB/% | |
| Operating temperature range | -30 to +80 °C | |
| Operating humidity range | 0 to 90 % RH(with no condensation) | |
| Storage temperature range | -40 °C to +70 °C | |
| Storage humidity range | 0 to 90 % RH(with no condensation) | |
| Power requirement | Constant Current Line Drive | |
| Drive current | 2 to 4.5 mA (rated 4 mA) | |
| Drive supply voltage | DC18 V to 26 V (rated 24 V) | |
| Drive supply voltage | C02 (BNC) | |
| TEDS version** | IEEE 1451.4 : 2004 (Template : Microphone with built-in Preamplifier Ver.1.0） | |
| Outer dimensions | Φ 13.2 X 91.9 mm | |
| Weight | Approx.41 g | |
| Accessory | Calibration chart × 1 Instruction manual × 1 MI-0301 (microphone holder for mounting tripod) × 1 |
|
* Reference environmental condition: 23 °C,50 % RH,101.3 kPa
* Applicable cable length is 30 m or less. Please note that if you extend it more than 30 m, it cannot be conformed to CE marking.
* For TEDS compatibility of measuring device and measurement amplifier to be connected, please contact your nearest distributor or send us an email (overseas@onosokki.co.jp).
Revised: 2023/09/25
