GRAS 40SC CCP Probe Microphone
Freq range: 2 Hz to 8 kHz
Dyn range: 40 dB to 160 dB
Sensitivity: 3 mV/Pa
Technology
Typical applications and use
- Acoustic-impedance measurements
- Exhaust-system measurements
- Near-field measurements
- Measurements at high temperatures
- Pressure-distribution measurements in small enclosures
Design
The GRAS 40SC is constructed with detachable stainless-steel probes tubes which guide the acoustic signal to a prepolarised microphone inside the housing of the 40SC. After being sensed by the microphone, the acoustic signal is passed on to an impedance-matching wave guide which eliminates unwanted internal reflections. The result is a smooth frequency-response ranging from 2 Hz up to 20 kHz. The internal microphone is connectedto an CCP preamplifier with a high dynamic range; ensuring a measurement range from approximately 40 dB to 160 dB re. 20 μ Pa.
The integrated BNC socket is for drawing power from, and delivering the signal to, a constant-current power supply, e.g. the GRAS 12AL CCP Supply, or any other compatible constant-current power supply.
The CCP Probe Microphone 40SC is internally compensated to equalize the internal pressure of the microphone with the static pressure at the probe’s tip . The static pressure within the 40SC will therefore adjust itself to the static pressure existing at the probe’s tip; which it does with a time constant of approximately 0.1 s.
The 40SC can be used with various probe lengths and is delivered with four standard probe lengths, i.e.: 20 mm, 40 mm, 80 mm and 160 mm. Intermediate lengths can be made by cutting these standard lengths. Also, the stainless steel tubes can be bent to a radius as low as 5 mm without downgrading the system’s acoustics. A flexible probe tube is also provided for use in measurements where stiff stainless-steel tubes are not practical. This does, however, slightly downgrade the system’s acoustic performance.
The right angled design of the 40SC makes it particularly well suited for measurements on exhaust-gas systems and other machinery in general as well as for scanning vibrating surfaces such as loudspeaker diaphragms and cabinets.
The compact size, low weight and all-stainless-steel construction of the 40SC make it robust, easy to handle and easy to mount.
Specifications
Dimensions
Where not specified, measures are in mm.
Length (housing) |
83.80 |
Diameter |
12.7 |
Probe tube outside diameter |
1.25 |
Probe tube inside diameter |
1 |
Cable diameter |
2.5 |
Cable length |
3 metres |
Ordering info
Included items
GRAS GR0265 |
Pistonphone adapter for stainless steel probe |
GRAS GR0266 |
Pistonphone adapter for flexible probe |
GRAS GR0267 |
Heat sink and tool |
GRAS RA0326 |
Calibration coupler |
GRAS GR0263 |
1.3 mm insert pin for calibration coupler |
GRAS GR0266 |
1.6 mm insert pin for calibration coupler |
GRAS YY0004 |
Pair of pliers |
GRAS YY0005 |
File |
GRAS MI0016 |
Silicon grease |
GRAS EK0018 |
Teflon tubing (L=0.5 m, Dia.: 1.6 mm) |
GRAS GR0258 |
20 mm probe tube |
GRAS GR0259 |
40 mm probe tube |
GRAS GR0260 |
80 mm probe tube |
GRAS GR0261 |
160 mm probe tube |
GRAS GR0401 |
Flexible probe tube |
GRAS SK5546 |
Needle (for cleaning the probe) |
Optional items
3 m BNC - BNC Cable |
|
GRAS AA0039-CL |
Customized Length BNC - BNC Cable |
2-Channel Power Module with gain, filters and SysCheck generator | |
2-Channel Universal Power Module with signal conditioning and PC interface |
|
Pistonphone, Class 1 |
|
Intelligent Pistonphone, Class 0 |
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.