18mm LCD,3 1/2 digits

Measurement functions

dB(A&C frequency weighting), Time weighting(Fast, Slow), Max hold, Max hold reset, AC output

Test range

3 ranges ( 30 – 70 dB,60 – 100 dB,90 – 130 dB )

Solution Analyze Degree

0.1 dB

Fine Indeed Degree

Time weighting & frequency weighting meet IEC 651 type 1, calibrating input signal on 94 dB
(31.5 Hz to 8 kHz), the accuracy of A weighting is specified as following:
31.5 Hz – ± 1.5 dB, 63 Hz -± 1.5 dB, 125 Hz – ± 1 dB,250 Hz – ± 1 dB, 500 Hz – ± 1 dB,
1 kHz -± 1 dB,2 kHz – ± 1 dB, 4 kHz – ± 1 dB, 8 kHz – + 1.5 dB to -3 dB

Frequency weightingwork

Characteristics of A & C.

A weighting – The characteristic is simulated as “Human Ear Listing” response. Typical, if making the environmental sound level measurement, always select to A weighting.

C weighting – The characteristic is near the “FLAT” response. Typical, it is suitable for checking the noise of machinery (Q.C. check) & knowing the sound pressure level of the tested equipment

The test frequency range

31.5 Hz to 8,000 Hz

School Positive Device

B & K (Bruel & kjaer), multi-fuction acoustic calibrator, model : 4226

Microphone types

Electric condenser microphone.

Microphone size

1/2 inch standard size.

Range selection

30 to 70 dB,60 to 100 dB,90 to 130 dB,40 dB on each step,with over & under range indicating

Time-weightedwork
(Fast / Slow)

Fast – t= 200 ms, Slow – t = 500 ms,
* “Fast” range is simulated the human ear response time weighting.
  “Slow” range is easy to get the average values of vibration sound level.
* The “Fast” & “Slow” time weighting range are designed to IEC 651 type 2 requirement

Correction methods

Build in external calibration VR, easy to calibrate on 94 dB level by screw driver.
Internal oscillation system, 1 KHz sine wave generator

Output signal

AC output – AC 0.4 Vrms corresponding to each range step.

Output terminal

3.5 phone output terminal is provided for connection with analyzer, level recorder, tape recorder.

Use the power

DC 9V battery x 2 PCs or equivalent,heavy duty or alkaline type.

Current consumption

Approx. DC 17mA.

0  to 50

Less than 80% RH

260×87×36 mm

450 g.(including battery)

Instruction Manual ……………………………………………. 1 PC
Carrying case…………………………………………………… 1 PC

94 dB Sound Calibrator, model : SC-940, model : SC-941