Cost-effective and durable sensors for the mid-infrasound to low-audio bandwidth.
The Model 21 and 25 are an excellent choice for any application requiring a high resolution infrasound sensor in a small form factor at a moderate cost. It excels ataccurately recording signals which span the low audio/infrasound boundary, such asexplosions and avalanches, and makes an excellent sensor for campaign styleexperiments because of its rugged construction. If your application requires a highquality infrasound sensor, the Chaparral Physics Model 21/25 provides you with acompact, robust solution with excellent value.
| Nominal Sensitivity | |
|---|---|
| High: | 2.0 volts/Pa @ 1 Hz, 18 Pa full scale range |
| Low: | 0.4 volts/Pa @ 1 Hz, 90 Pa full scale range |
| Individual sensor’s calibrated value is +/-5% from nominal. Calibration value istraceable to the Los Alamos National Laboratory (LANL) calibration chamber. |
| Output | |
|---|---|
| Output Type: | Differential |
| Maximum | 36 volts peak-to-peak (signal+ to signal-) |
| Frequency Response | Flat to within +0, -3 dB from 0.1 Hz to 200 Hz |
| Flat to within +0, -0.5 dB from 0.3 Hz to 50 Hz | |
| Self Noise | Less then 0.63µPa2/Hz @ 1 Hz (-62dB Pa2/Hz, rel to 1 Pa) |
| Less than 3 mPa RMS 0.1 to 40 Hz | |
| Less than 0.8mPa RMS 0.5 to 2 Hz | |
| Dynamic Range | 99dB high gain, 113dB in low gain @ 0.5 Hz to 2 Hz |
| Output Impedance | 150Ω non-reactive, (recommend load >10kΩ)(Recommended less than 10,000pf loading) |
| Short circuit protected | signal+ to signal–, and signal to ground |
| Power Requirements | |
|---|---|
| DC Source | 12 volts (9-18 volts) DC, reverse voltage protected. |
| Current Drain | Less than 40 ma @ 12 v |
| Physical | |
|---|---|
| Sensor will function in any position or attitude. Sealed to IP-64 with acoustic inlet sealed and mating electrical connector installed. | |
| Operating Temperature | -40℃ to + 65℃ |
| Humidity | 95% (non-condensing) |
| Dimensions | 16.5” (42 cm) maximum height, 9.9” (25 cm) maximum diameter |
| Weight | 17.6 lbs (8 Kg), for 4-port version |
| Std. Acoustic Inlets | 4 inlet ports (maximum 12), male, Garden-Hose-Thread,and a calibration port. Total fore-volume of a 4 port Model50A with capped GHT inlets is ~55 cubic cm. |
