CAL511 Microphone Calibrator 94/104 dB SPL
The CAL511 accepted internationally 1 kHz represents the "0 dB" reference point of A, B, C Weighting and other filters utilized in acoustic measurement. The Pistonphone - a mechanical sound source - offers a slightly higher degree of accuracy at a substantial increase in cost. In addition, the 200 or 250 Hz operating frequency is mechanically limited and not suited for measurements of filtered inputs. The 0.2 dB accuracy is quickly lost in the 0.7 to 1.5 dB tolerances acceptable for weighting filters at frequencies around 250 Hz. It's 94 dBSPL due to the International standards have established 1 Pascal (Pa) as 94 dBSPL. This reference point is now accepted for specifying the sensitivity of microphones. The uBar found in some specifications refers to 74 dBSPL (20 dB less than 1 Pa).
The CAL511 calibrator is easy to use.  Attach the microphone to be tested to your  Audio Analyzer (such as a Gold-Line-Europe DSP30)  and insert  the microphone into  the opening in the calibrator.  Press a switch to activate the  Calibrators  test signal.  The signal is at a specified level .  Your RTA will show the level produced by your microphone to validate that your microphone and RTA are in agreement with the calibrator
CAL511 Package Contents:
l CAL511 Microphone Calibrator 94/104 dB SPL
l Certification calibration report
l Manual
- 1000 Hz  
  0 dB Reference Point for: A, B, C, D Weighting
- 2 Output Levels: Permits Range testing
  94 dBSPL 1 Pa
  104 dBSPL  
- Accuracy: Meets IEC942
  0.3 dB @ 23 C Type 1L  
  0.5 dB 0 to 50 C  
Power: 9Vdc Alkaline Battery (NEDA 1604A)
Size: Diameter 1 1/8 inches
  1/2 inch adaptor Q3 (Included with CAL511 )
Approvals: CE, RoHS and WEEE