Dorrough electronics 40-A2 Loudness monitor

Input Impedance

20 kOhm balanced
10 kOhm single-ended, +/- 2%

Common Mode Rejection Ratio

80 dB at 60 Hz
60 dB at 20 kHz (balanced mode)

Input Sensitivity

-10 dB for full-scale display

Maximum Input Level

+24 dB before clipping

Signal Path Bandwidth

10 Hz - 25 kHz, +/- .25 dB

Signal Path Distortion

>1% THD at 1 kHz, +24 dB input

Sum Error

>0.1 dB at 1 kHz

Difference Error

>0.1 dB at 1 kHz

Display Resolution

40 LEDs, 1 dB/LED

Step Size Error

+/- 0.25 dB

Absolute Error

+/- 0.25 dB (Full Scale -39 dBu)

Drift

+/- 0.25 dB

Average Time Constant

600 mS, +/- 6%

Peak Acquisition Period

10 uS, to full-scale, sine input 25kHz

Peak Attack Period

Virtually Instantaneous

Peak Decay Period

180 mS, from full-scale to all LEDs off

Display Update Rate

Approximately 10 mS

Display Duty Cycle

Display Time, AVERAGE, PEAK HOLD - 75%
Display Time, PEAK - 100%

Power Supply Input Range

117/237 VAC RMS, -20% to +10%, 50-60 Hz

Calibration Controls

None needed

User Controls

Left/Right input sensitivity
Option DIP Switch:
A) Peak Auto [ON]
B) Difference Mode [ON/OFF]
C) Over Level Alarm [ENABLE]
D) Under Level Alarm [ENABLE]
E) Auto ARMP

User Port

DB-9 Connector:
A) Alarm relay closure contacts,1 form C, 1A, 30V AC or DC
B) Mode control switch (user supplied)
C) PEAK function switch (user supplied)

Dimensions (WxDxH)

8.5 x 6.5 x 2.8" (215.9 x 165.1 x 71.1mm)

Weight

2.3 lb (1.04 kg)