GRAS 67SB Blast Probe Microphone according to ANSI S12.42

Freq range: 10 Hz to 20 kHz
Dyn range: 52 dB(A) to 174 dB


The 67SB Blast Probe is designed as a reference microphone for impulse measurements according to the ANSI S12.42 standard. The 67SB can measure impulse signals with an A-duration of 0.5 ms ≤ impulse ≤ 2.0 ms, and it has a working range of 10 Hz – 20 kHz. The 1/8” reference microphone inside the 67SB is ideally suited for capturing impulsive signals with a very fine time resolution. This microphone has an upper limit of 174 dB in the dynamic range.

The 67SB is equipped with a 1/8" reference microphone which is designed to capture impulsive noise with a very short duration. The 67SB is provided with a 1/4" threaded hole for monting the 67SB directly on a tripod e.g. AL0006.

The design and concept of the 67SB, and the microphone and preamplifier, comply with the following standards:
• ANSI S12.42 – “Methods for the Measurement of Insertion Loss of Hearing Protection Devices in Continuous or Impulsive Noise Using Microphone-in-Real Ear or Acoustic Test Fixture Procedures”
• IEC Standard 61094-1 – “Specifications for Laboratory Standard Microphones”

The 67SB has a length of 410 mm.


Frequency range (±2 dB)
10 to 20 k
Dynamic range lower limit with GRAS preamplifier
Dynamic range upper limit
Microphone venting
Output impedance
Temperature range, operation
°C / °F
-30 to 70 / -22 to 158
Temperature range, storage
°C / °F
-40 to 85 / -40 to 185
Static pressure coefficient @250 Hz
-0.01 at 25 °C
Humidity range non condensing
% RH
0 to 95
Humidity coefficient @250 Hz
dB/% RH
Influence of axial vibration @1 m/s²
dB re 20 µPa
Connector type
3 m 7-pin LEMO
CE/RoHS compliant/WEEE registered
g / oz
650 /22.9

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Ordering info


GRAS RA0246 Calibration clip for use with Pistonphone
GRAS GR1243 Pistonphone adapter
GRAS YY0012 1.5 mm Hex key
GRAS LI0056 Manual


GRAS 12AK 1-ch LEMO Power Module with gain, filters and SysCheck generator
GRAS AA0008 3 m LEMO extension cable
GRAS AA0009 10 m LEMO extension cable
GRAS 42AP Intelligent Pistonphone
GRAS AL0006 Tripod

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

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