can be used as a sound level meter by attaching the microphone to a bracket. It
can also be mounted on a tripod for area surveys.
The MICRO-15 is powered by a single 9-volt alkaline transistor battery with
an 80-hour battery life. A low battery indication will be displayed 8 hours before
the end of life of an alkaline battery. See page 14 for method of testing battery.
SPECIFICATIONS
Standards: ANSI S1.4-1983 type 2
ANSI S1.25-1978
IEC 651 type 2 (sound level reads slow response level once
each second).
Detector: True RMS; 63 dB pulse range and crest factor.
Readout:
4-digit liquid crystal display.
Dose: .01 to 19999%.
Time: hours, minutes, and seconds.
Sound level: 0.1 dB.
Integrated sound level: 0.01 dB.
Microphone: 8 mm (1/4 inch), omnidirectional PZT ceramic with collar clip
and 36-inch cable.
Battery: Single 9-volt alkaline, 80-hour battery life.
Battery Indicator: Shows at least 8-hour battery life is available.
Calibration: External calibrator.
Temperature: -10 to +50°C operating; - 40 to +60°C storage (battery
removed).
Humidity: 0 to 95% R.H.
Magnetic Field Effects: Negligible below 4000 R/M (50 oersteds) at 50 to 60
Hz.
Size: 2.5 x 5.1 x 1.3 inches (64 x 130 x 33 mm).
Weight: 11 ounces (315 grams) including battery and coverplate.
Construction: CMOS microprocessor in rugged aluminum housing with
tamper-, water-, and dust-resistant security cover.
PRINCIPLES OF OPERATION
General
The MICRO-15 Noise Dosimeter uses an 8-mm omnidirectional
ceramic" microphone buffered by a high impedance FET input stage. The
electronics utilizes low power circuitry for long battery Hie, maximum stability,
and high reliability over a wide range of environmental conditions. A block
diagram of the MICRO-15 is shown in Figure 2.