Question 1

What is a Type 2 sound level meter?

Accepted Answer

Type 2, also written Class 2, is the general-purpose accuracy grade defined in IEC 61672 and ANSI S1.4. The DT-805 meets IEC 61672-1 Type 2 with plus or minus 1.5 dB accuracy and 0.1 dB resolution; the SL-4023SD meets IEC 61672 Class 2; the DT-8852 meets ANSI S1.4 Type 2 and IEC 651 at plus or minus 1.4 dB.

Question 2

Do I need a calibrator with my sound level meter?

Accepted Answer

A calibrator puts a known sound pressure level on the microphone so you can confirm the meter reads true before and after a survey. The SC-941 delivers 94 dB at 1 kHz for a 0.5 inch microphone. The SC-942 delivers 94 dB and 114 dB and fits both 0.5 inch and 1.0 inch microphones using the supplied adaptor.

Question 3

What does OSHA 1910.95 require for occupational noise?

Accepted Answer

OSHA 29 CFR 1910.95 Table G-16 permits 90 dBA for 8 hours a day, measured on the A scale at slow response. At or above an 8-hour time-weighted average of 85 dBA, the action level defined in paragraph (c)(2), the employer must administer a continuing, effective hearing conservation program.

Question 4

What is the difference between A-weighting and C-weighting?

Accepted Answer

A-weighting shapes the meter's response to approximate how the human ear hears loudness, and occupational noise limits are written in dBA. C-weighting is much flatter and keeps low-frequency energy in the reading. The DT-805, DT-8852 and SL-4013 all switch between A and C across 31.5 Hz to 8 kHz. The SL-406 multimeter adapter is A-weighted only.

Question 5

What is in the SLM-ProKit-1000?

Accepted Answer

A DT-805 sound level meter and an SC-942 calibrator that produces a 1000 Hz tone at 94 dB or 114 dB, so the meter can be set against a known reference before a survey. It also ships with a CA-05 padded carrying case, three 9 Vdc batteries and a calibration tool. The kit is $459; the SLM ProKit-1000-CC is $559.

Question 6

Which sound level meter logs a full shift of data?

Accepted Answer

The SL-4023SD at $264 writes each reading to an SD card of 1 GB to 16 GB with a date and time stamp, at an interval you set from 1 second to 60 minutes, and connects over RS232 or USB. The SL-4023SD-CC at $389 is the same meter with a calibration certificate traceable to NIST standards.

Question 7

Can I measure sound level without buying a dedicated meter?

Accepted Answer

The SL-406 adapter at $59 turns a digital multimeter into an A-weighted sound level meter reading 30 to 130 dB across three ranges, with an output of 1 mV per decibel, so 0.085 V on the multimeter is 85 dB.

Paranormal Research Instruments by Gary Galka · Professional Test Meters by DAS Distribution

Measure sound with lab accuracy