| 4. Once upon a time we all used the B&K 4007, which was around 2.27mV/pa which would be .0027 on the input calibration. Typically our newer TEF05A and MK10 are around l0mV/pa or 0.01. Each mV that you are off will change your readings by approximately 1dB. So, a calibration defaulted for the 4007, will claim that the level is around 8dB high when you use a TEF05A. It is rare to see the 0dB reference wrong. For SPL it should be 20u pascals which is .00002. Where people get into trouble is where they were doing impedance plots and had the reference set to 1 volt. This will result in the TEF claiming that your SPL is very low. |
