Low class sound level meters - Models 81CA - 82CA

Models 81CA/82CA

  • Automatic C-A measurement mode

  • Ideal for HML method of hearing protection calculation

  • Hearing protection measurements have never been easier;

  • The C-A mode ensures automatic measurement calculation

  • Expands the original concept of the basic Assessor for those with noisy work places that prefer an affordable but legal method of specifying suitable hearing protection measurement

  • Batteries:  2xАА (LR6)

  • Working at temperature: from  -10°C to +50°C

  • Dimensions: 340 mm x 75 mm x 25 mm (Class 1) /300 mm x 75 mm x 25 mm (Class 2)

  • Weight: 450g


The Models 82CA & 81CA are the ideal instruments for those who do not want to pay extra for an instrument with 1:1 Octave Band Filters because the HML method (High, Medium and Low), is an established and accepted method of calculating hearing protection.

All hearing protection (PPE) should be supplied by the manufacturer with attenuation (reduction) values for each of the H, M and L values. By knowing the‘C’ and ‘A’ weighted Leq values and the difference between them you can use either a spreadsheet or simple formula to prescribe suitable hearing protection for your workforce.

C-A measurement mode

By just pressing the C-A button, the instrument will automatically switch to ‘C-A’Measurement Mode. A blue LED indicator shows that you are now measuring in ‘C-A’ mode rather than the normal ‘Broadband’ mode.

The instrument will make an Leq measurement with dB(C) Weighting (LCeq) and will continue until the average level has settled. When the level has settled, the instrument will switch to dB(A) and repeat the process with ‘A’ weighting. When this level has also settled, the instrument will display the LCeq, LAeq and in large digits, the result LCeq-LAeq value on the screen.

Comparison table

Kind Definition Accuracy Application
Class 1 Precise assessment of laboratories ±0,7 db In the enviorement, acoustic of building, vehicules
Class 2 Grade for general purpose ±1,0 db Work space, basic enviorements, motorsports