MODEL HN405
• Meets IEC 651 Type 2 specifications
• 3 Ranges, 35 to 130 dB
• “A" frequency weighting
• Fast time weighting
• Data Hold

MODEL HN404
• Meets IEC 651 Type 1 specifications
• 3 Ranges, 30 to 130 dB,
• MAX HOLD, DATA HOLD
• A/C frequency weighting
• Fast/Slow time weighting
• AC output
• Internal 94 dB calibration

Model No.  Mfg. No.   Description
HN405   SL-4010    Sound Level Meter
HN404   SL-4022    Sound Level Meter