G.R.A.S. 46BD 1/4" CCP Pressure Standard Microphone Set

Freq range: 4 Hz to 70 kHz
Dyn range: 44 dB(A) to 166 dB
Sensitivity: 1.45 mV/Pa
  • 46BD 1/4


The 46BD is a 1/4" CCP microphone set for pressure measurements. Its LEMO equivalent is G.R.A.S. 46BP

The set consists of the 1/4" pressure microphone 40BD and the 1/4" preamplifier 26CB with a Microdot coaxial connector.

This combination was chosen to save you time and give you the best possible properties and reliability in the microphone/preamplifier match. Your workflow is optimized and typical handling errors are minimized.

Not only have we made a set of the best possible combination of microphone and preamplifier, we have also included TEDS, the Transducer Electronic Data Sheet standard according to IEEE-1451.4. Multi-channel users appreciate having an intelligent transducer, like 46AF, that can supply properties, types, and calibration data directly to measurement platforms that support TEDS.

The signal wire in the CCP transducer is used for reading the TEDS information directly from the transducer.

46BD is individually factory-calibrated and delivered with a calibration chart stating its specific open-circuit sensitivity and pressure frequency response.

Typical applications and use

The 40BD is ideal for sound pressure measurements, as well as high frequency and high level pressure measurements. It is suitable for general purpose acoustic measurements in couplers and at boundaries.


The 46BD uses the Microdot coaxial connector, which requires an input module that supports this technology.

For more information, see System Setup.

TYPE (Microphone features) P
Frequency range (±1 dB) Hz 10 to 25 k
Frequency range (±2 dB) Hz 4 to 70 k
Dynamic range lower limit with G.R.A.S. preamplifier dB(A) 44
Dynamic range upper limit with G.R.A.S. CCP preamplifier dB 166
Set sensitivity @ 250 Hz (±3 dB) mV/Pa 1.45
Set sensitivity @ 250 Hz (±3 dB) dB re 1V/Pa -57
Output impedance Ω <50
Output Voltage Swing, min. @ 24-28 V CCP voltage supply Vp 8
Power supply min. to max. mA 2 to 20
DC bias voltage, typ. V 12
Microphone venting Rear
IEC 61094-4 Compliance WS3P
Temperature range, operation °C / °F -30 to 70 / -22 to 158
Temperature range, storage °C / °F -40 to 85 / -40 to 185
Temperature coefficient @250 Hz dB/°C / dB/°F -0.01 / -0.006
Static pressure coefficient @250 Hz dB/kPa -0.008
Humidity range non condensing % RH 0 to 95
Humidity coefficient @250 Hz dB/% RH -0.001
Influence of axial vibration @1 m/s² dB re 20 µPa 55
TEDS UTID (IEEE 1451.4) 27 v. 1.0
Connector type Microdot 10/32
CE/RoHS compliant/WEEE registered Yes / Yes/Yes
Weight g / oz 8 / 0.282

Typical frequency response (without protection grid)

Free-field corrections for different angles of incidence

Optional items

G.R.A.S. AA0070

3 m Microdot - BNC Cable

G.R.A.S. AA0073-CL

Customized Length Microdot - BNC Cable

G.R.A.S. AA0087-CL

Customized Length Microdot - Microdot Cable

G.R.A.S. AL0029

1/4" Microphone Holder, POM

G.R.A.S. AL0013

1/4" Microphone Holder, Stainless Steel

G.R.A.S. AL0005

Swivel head

G.R.A.S. AL0006


G.R.A.S. RA0022

1/4" Nosecone

G.R.A.S. AM0071

Windscreen for 1/4" Microphones

G.R.A.S. RA0127

Rain-protection cap for 1/4” microphones

G.R.A.S. 12AL

1-Channel CCP Power Module with A-weighting filter

G.R.A.S. 12AQ

2-Channel Universal Power Module with signal conditioning and PC interface

G.R.A.S. 42AB

Sound Calibrator, Class 1

G.R.A.S. 42AP

Intelligent Pistonphone, Class 0