The High Intensity Acoustic Sensors (Microphones) Models 765M30 and 765M35 are developed for the monitoring of gas-borne sound in industrial applications. These sensors are compatible with type 316 stainless steel diaphragms and are designed for usage in corrosive settings.
When paired with the all-welded structure, the electrically isolated, coaxial stainless steel hermetic connection creates a perfect hermetic seal.
Electrically, Models 765M30 and 765M35 use piezoceramic sensing elements in a balanced and floating design to enable improved rejection of electrical noise in a variety of industrial settings. The inherent acceleration sensitivity of the acoustic element is eliminated by an inbuilt accelerometer. When utilized with a real differential input amplifier, the best results are obtained.
For customized versions of this sensor, contact the manufacturer.
- High temperature to +500 Deg F
- Vibration compensated
- Electrically isolated
- High sensitivity (2100 pC/psi)
Specifications
Transfer/Electrical
Table 1. Source: Columbia Research Laboratories, Inc.
| Transfer / Electrical |
765M30 |
765M35 |
| Charge Sensitivity |
2100 +/-300 pC/psi |
| Frequency Response |
2 Hz To 8,000 Hz |
| Dynamic Range |
0.28 x 10-4 to 10 psi (191 dB SPL Max.) |
| Vibration Sensitivity |
1.0 pC/g Typical, 2.0 pC/g Max. |
| Avg Temp Coeff of Sensitivity |
0.08% / Deg F |
| Transducer Capacitance |
14,500 pF +/-15% |
| Insulation Resistance |
100 Megohms Min., 50 VDC Test |
| Isolation Resistance |
100 Megohms Min., 50 VDC Test |
| Dielectric Strength |
550 Vrms, 60 Hz, Element to Housing |
Environmental
Table 2. Source: Columbia Research Laboratories, Inc.
| Environmental |
765M30 |
765M35 |
| Vibration Limit |
100 g Max. (Sine) |
| Shock Limit |
1,000 g Max., 0.25 mSec |
| Temperature Range |
-10 To +500 Deg F (-23 To +260 Deg C) |
| Humidity3 |
0 To 100% R.H. |
| Static Pressure |
3,000 psi Max. (Diaphragm) |
| Electromagnetic Sensitivity |
0.005 g (Equiv / 100 Gauss) |
Physical
Table 3. Source: Columbia Research Laboratories, Inc.
| Physical |
765M30 |
765M35 |
| Configuration |
Balanced Floating Compression |
| Size |
1.375 In. Hex x 2.25 In. H (35.0 mm Hex x 57.2 mm H) |
| Weight |
7.0 Oz (200 Gm) |
Material
Body & Diaphragm |
Type 316 Stainless Steel |
| Electrical Interface |
Isolated 10-32 Coaxial Connector |
Isolated 10-32 Coaxial Connector
Supplied with 1/2-14 NPSM
Straight Pipe Thread for Armored Shielding |
| Mounting |
1.125 – 12 UNF-2A Straight Thread |
NOTE: The unit is hermetically sealed when the connector is mated or protected.
Image Credit: Columbia Research Laboratories, Inc.
Accessories Supplied
- Standard Calibration Data
- Low Noise Cable Assembly (3M) (300 pF)
- Hardwood Storage Case