User Manual
HT155 - HT157
EN - 56
10. TECHNICAL SPECIFICATIONS
10.1. TECHNICAL SPECIFICATIONS
Uncertainties are referred to a temperature of 23°C±5°C with relative humidity <80%UR
Measuring range
Weighting type A: 25 140dB
Weighting type C: 30 140dB
Weighting type Z: 35 140dB
SLM level Peak C: 50 143dB
Ranges [dB]
0
90 10 100 20
110 30
120 40 130 50
140
Weighting A
25
90 25
100 25
110 30
120 40 130 50
140
Weighting C
30 90 30
100 30
110 30
120 40 130 50
140
Weighting Z
35 90 35
100 35
110 35
120 40 130 50
140
Peak C
50 93 50
103 50
113 50
123 60 133 70
143
CAUTION
For sensitivity values <50mV/Pa, the measuring range is higher. For
example, with a microphone with a sensitivity of 40mV/Pa (-28dB), the
measuring range increases by 2dB and the reference value on the display
passes to range 42 132dB
We recommend using a ½” pre-polarized microphone with a sensitivity of
50mV/Pa, frequency range: 10Hz 20kHz, basic noise <16dB(A)
Linear dynamic range: >90dB
Resolution: 0.1dB (statistic), 0.01dB (1/1 and 1/3 octave)
Frequency range: 10Hz 20kHz (0.2dB); 1Hz 23kHz (1.0dB)
Gain range: -10dB, 0dB, 10dB, 20dB, 30dB, 40dB
Internal error: 0.1dB
Internal noise voltage: <4V (1Hz 23kHz linear)
Background noise: <13dB(A), 15dB(C), 25dB(Z)
Total noise: <18dB(A), 23dB(C), 28dB(Z)
Voltage measuring range: 15V 10V (TRMS)
Frequency weighting: A/C/Z
Time constants: Fast, Slow, Impulse, Peak C+, Peak C-
Internal A/D converter: 24 bits
Anti-aliasing filter: cut-off frequency 23.5kHz, attenuation 100dB
Sampling frequency: 20.8s (48kHz)
Integration time: 1s 24h at preset or custom intervals
Internal memory: 64kByte flash memory
Memory capacity: max 128 groups/ max 256 calibrations
Analogue output: AC, ratio 1mV/0.1dB, max voltage 3.2V
Output interface: mini-USB 1.1 and 2.0 compatible
Connection to USB pen drive: recommended TRASCEND JF V30 2GB
Microphone: ½” with prepolarized condenser with pre-amplifier,
sensitivity: 50mV/Pa, frequency range:
10Hz20kHz, noise <16dB(A)