PLACID PMP21 Microphone
PLACID PMP21 is 1/2” prepolarized free field measurement microphone. It is intended to be used in IEC Class 1 Sound Level Meters, and other noise measurements where Class 1 accuracy is required.
All the microphones are going through solid environmental testing, which includes high temperature ageing and high humidity ageing.
Specification
Basics
The PLACID PMP21 is a high-precision condenser microphone manufactured in compliance with the IEC 61094-4 requirements and classified as a class 1 microphone. The PMP21 microphone is optimized for free-field measurements.
As all PLACID microphones, the PMP21 comes with an individually calibration certificate.
Connectivity
The PLACID PMP21 microphone requires a standardized 1/2″ BNC preamplifier that does not need to provide polarization.
Uses
The PMP21 is a robust and stable microphone and is being used as an all-round free field microphone suitable for laboratory as well as field jobs.
Daily usage
PLACID recommends calibration before and after each measurement with a calibrator.
Individual calibration
All PLACID microphones are being calibrated in a controlled laboratory environment using traceable calibration equipment complying with ISO17025 standards. We recommend that all PLACID microphones are re-calibrated every year to guarantee an optimized usage. PLACID Traceable Calibration is performed by our qualified staff and under controlled conditions according to the procedures and standards such as ISO17025
Quality
All PLACID microphones are made of high- quality materials that will ensure long stability and durability.
The microphone diaphragm, body, and protection grid are made of high-grade stainless steel, which makes the microphone resistant to physical damage. PLACID offers 2 years warranty against defective materials and workmanship.
| DATASHEET PLACID PMP21 MICROPHONE | |
| Materials | |
| Grid | Copper （Nickel plated） |
| Housing | Stainless Steel |
| Diaphragm | Nickel |
| Back Plate | Stainless Steel |
| Insulator | Crystal Quartz |
| Electret | Teflon |
| Acoustical Properties | |
| Frequency Response | Free-field |
| Open Circuit Sensitivity | 50mV/Pa ±2dB |
| Equivalent Noise Level | < 16 dB(A) |
| T.H.D | < 3% at 146dB SPL |
| Polarization Voltage | 0 V |
| Capacitance | 16.0 pF |
| Equivalent Air Volume | 230 mm3 at 250 Hz. |
| Diaphragm Resonance Frequency | 16 kHz. |
| Pressure Vent | Rear |
| Operating Temperature Range | -30 C, ~ 90 C |
| Temperature Coefficient | < -0.012 dB/℃ (at 250Hz, -10 ~ 50 °C;) |
| Humidity Coefficient | < 0.1 dB/% (at 250Hz, 0 ~ 98 %RH) |
| Pressure Coefficient | < -0.01 dB/kPa (at 250 Hz, 65 kPa – 108 kPa ) |
The typical frequency response for PMP21
Pressure to free field correction
when using an electrostatic actuator of PMP21 with Protection Grid
| (unit: dB) | |||||||
| Frequency kHz |
0º |
30º |
60º |
90º |
120º |
150º |
180º |
| 1.00 | 0.2 | 0.1 | 0.0 | -0.1 | -0.2 | -0.2 | -0.1 |
| 1.25 | 0.3 | 0.3 | 0.1 | -0.1 | -0.2 | -0.2 | 0.0 |
| 1.60 | 0.4 | 0.4 | 0.1 | 0.0 | -0.2 | -0.2 | 0.1 |
| 2.00 | 0.5 | 0.5 | 0.2 | 0.0 | -0.2 | -0.2 | 0.1 |
| 2.50 | 0.6 | 0.5 | 0.2 | 0.1 | -0.3 | -0.2 | 0.1 |
| 3.15 | 0.8 | 0.5 | 0.1 | 0.0 | -0.4 | -0.3 | 0.2 |
| 4.00 | 1.0 | 0.8 | 0.2 | 0.0 | -0.5 | -0.6 | -0.4 |
| 5.00 | 1.5 | 1.2 | 0.3 | 0.0 | -0.9 | -0.9 | -0.5 |
| 6.30 | 2.2 | 1.9 | 0.9 | 0.1 | -0.8 | -0.8 | -0.3 |
| 8.00 | 3.3 | 2.7 | 1.4 | 0.1 | -0.9 | -0.9 | -0.1 |
| 10.00 | 4.6 | 3.9 | 1.9 | -0.2 | -1.7 | -1.6 | -0.4 |
| 12.50 | 6.5 | 5.7 | 3.4 | 0.7 | -1.0 | -0.8 | 0.7 |
| 16.00 | 8.0 | 6.7 | 3.4 | -0.5 | -3.0 | -2.5 | -1.0 |
| 20.00 | 9.0 | 7.2 | 2.5 | -2.7 | -5.8 | -5.5 | -3.5 |
| Dimensions | ||||||||
|
Dimensions |
d1 |
d2 |
l1 |
l2 |
d4 |
d5 |
d3 |
Total L |
| IEC 61094-4
Requirements for WS2F |
13.2 |
12.7 |
3.6-4.6 |
>2.2 |
3-5 |
>7.8 |
11.70-
60UNS- 2B |
N/A |
|
PMP21 |
13.20 |
12.68 |
4.30 |
4.30 |
3.01 |
7.90 |
11.70-
60UNS- 2B |
16.50 |
| Height (Single Membrane) | 2.8 mm | |||||||
| Height(from the top of membrane to the end of Housing) | 15.8-16.3mm | |||||||
