HT HT155 User manual

Copyright HT ITALIA 2011 Release EN 1.02 - 28/12/2011
HT155 – HT157
User manual

HT155 - HT157
EN - 1
Table of contents:
1. PRECAUTIONS AND SAFETY MEASURES..................................................................3
1.1. Preliminary instructions....................................................................................................3
1.2. During use........................................................................................................................3
1.3. After use...........................................................................................................................3
2. GENERAL DESCRIPTION..............................................................................................4
3. PREPARATION FOR USE..............................................................................................5
3.1. Initial inspections..............................................................................................................5
3.2. Instrument power supply..................................................................................................5
3.3. Calibration........................................................................................................................5
3.4. Storage.............................................................................................................................5
4. OPERATING INSTRUCTIONS........................................................................................6
4.1. Instrument description......................................................................................................6
4.1.1. Front panel.................................................................................................................... 6
4.1.2. Output interface............................................................................................................. 6
4.2. Description of function keys.............................................................................................7
4.3. Analogue output description.............................................................................................7
4.4. Display contrast adjustment.............................................................................................8
4.5. Turning ON/OFF the instrument ......................................................................................8
4.6. Configuration of measuring parameters...........................................................................9
4.6.1. Foreword....................................................................................................................... 9
4.6.2. Programming menu interface........................................................................................ 9
4.6.3. Defining the measure name........................................................................................ 11
5. CARRYING OUT MEASUREMENTS............................................................................13
5.1. Statistic analysis of noise...............................................................................................13
5.1.1. Initial operations.......................................................................................................... 13
5.1.2. Statistic analysis operations........................................................................................ 14
5.1.3. 24-hour analysis operations........................................................................................ 17
5.1.4. Integration analysis operations.................................................................................... 21
5.2. Noise analysis in 1/1 and 1/3 octave band (HT157 only)...............................................24
5.2.1. Initial operations.......................................................................................................... 24
5.2.2. Octave band analysis (1/1).......................................................................................... 25
5.2.2.1. Operations for sections LIST, GRAPH and TOTAL...................................................25
5.2.3. Analysis in third-octave band (1/3).............................................................................. 30
5.2.3.1. Operations for sections LIST, GRAPH.......................................................................30
5.2.3.2. Operations in TOTAL section.....................................................................................33
6. INSTRUMENT ACOUSTIC CALIBRATION...................................................................35
6.1.1. Foreword.....................................................................................................................35
6.1.2. Preliminary operations................................................................................................. 35
6.1.3. Acoustic calibration with calibrator HT151 .................................................................. 37
6.1.3.1. Replacing the calibrator battery.................................................................................38
6.1.3.2. Calibration result display............................................................................................39
6.1.4. Direct acoustic Calibration........................................................................................... 39
7. OPERATIONS WITH THE MEMORY............................................................................40
7.1. Recalling results on the display......................................................................................40
7.1.1. Recalling the statistic analysis data on the display ..................................................... 41
7.1.2. Recalling the 24H analysis data on the display........................................................... 42
7.1.3. Recalling the integration measurement data on the display........................................ 44
7.1.4. Recalling the data of the octave band analysis (1/1) on the display ........................... 45
7.1.4.1. Recalling the data of the analysis in Total octave band (1/1).....................................46
7.1.5. Recalling the data of the analysis in third-octave band (1/3) on the display ............... 47
7.2. Data transfer onto USB Pen Drive.................................................................................48
8. OPERATIONS WITH SOUNDVIEW SOFTWARE.........................................................49

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8.1. Foreword........................................................................................................................49
8.2. Minimum system requirements......................................................................................49
8.3. Installing the driver USB.................................................................................................49
8.4. Use of SoundView software...........................................................................................51
8.4.1. Copy and Print commands.......................................................................................... 51
8.4.2. File menu..................................................................................................................... 52
8.4.3. View menu................................................................................................................... 53
8.4.4. Name Menu................................................................................................................. 53
8.4.5. Result menu................................................................................................................ 54
8.4.6. Calibration menu......................................................................................................... 54
8.4.7. Help menu................................................................................................................... 54
9. MAINTENANCE ............................................................................................................55
9.1. General information........................................................................................................55
9.2. replacing the batteries....................................................................................................55
9.3. Cleaning the instrument.................................................................................................55
9.4. End of life .......................................................................................................................55
10. TECHNICAL SPECIFICATIONS.............................................................................56
10.1. Technical specifications..........................................................................................56
10.2. Statistic analisys chararcteristics............................................................................57
10.3. Characteristics of analysis in 1/1 and 1/3 octave band (HT157 only)....................57
10.4. Characteritics of portable calibrator HT151............................................................57
10.5. General characteristics...........................................................................................58
10.6. Accessories ............................................................................................................58
11. SERVICE................................................................................................................59
11.1. Warranty conditions................................................................................................59
11.2. Service....................................................................................................................59
12. APPENDIXES.........................................................................................................60
12.1. Appendix 1 – Frequency weighting characteristics................................................60
12.2. Appendix 2 – characteristics of 1/3 octave band filter............................................61
12.3. Appendix 3 – frequency weighting A, C .................................................................64
12.4. Appendix 4 – characteristics of 4Hz high-pass digital filter....................................65

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1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with the directives regarding electronic
measuring instruments. For your safety and to prevent damaging the instrument, we
recommend following the procedures described in this manual and carefully reading all
notes preceded by the symbol .
Before and during measurements, carefully observe the following instructions:
Do not perform any measurement in humid environments.
Do not perform any measurement in the presence of gas, explosive or flammable
material, or in dusty areas.
Do not perform any measurement when anomalies are found in the instrument, such as
deformations, breaks, substance leaks, no display view, etc.
In this manual and on the instrument, the following symbols are used:
Warning: observe the instructions reported in the manual. An improper use could
damage the instrument or its components.
Instrument complying with the standards relevant to the EC mark
1.1. PRELIMINARY INSTRUCTIONS
CAUTION
The instrument has been designed for measuring sound pressure levels
(SPL) from 25dB to 140dB with frequency ranging from 10Hz to 20kHz
We recommend following the usual safety rules to protect the instrument
against improper use
After a long storage period or if the instrument has been used under critical
conditions, recalibrating the instrument is recommended (see § 6)
Check if the batteries are correctly inserted
1.2. DURING USE
We recommend carefully reading the following recommendations and instructions:
CAUTION
Failure to observe the warnings and/or instructions may damage the
instrument and/or its components or generate a danger for the operator.
Do not perform measurements in environmental conditions not within the
limit values indicated in § 10.5

A
lways use the windproof protection when carrying out measurements in
environments where air currents are present
Do not subject the instrument to strong mechanical stress and keep the
microphone dry
1.3. AFTER USE
When measurements are completed, turn off the instrument.
If the instrument is not to be used for a long time, remove the battery.

HT155 - HT157
EN - 4
2. GENERAL DESCRIPTION
This manual refers to models HT155 and HT157. In the manual, the generic term
“instrument” refers to both devices and, if not otherwise indicated, characteristics are to be
considered as common to both models
The instrument has the following functions:
Measurement of sound pressure level (SPL) Type 1
Real-time and statistic analysis
Octave band and in 1/3 octave band analysis (HT157 only)
Measures weighted in frequency by means of A, C and Z curves and F, S impulses
Fast, Slow, Impulse, PeakC+, Peak C- integrations
Measurement of noise equivalent levels (Leq)
Inner memory for saving measures and recordings
AC analogue output for connection to external dataloggers
USB interface for connection to PC and/or USB pen drive
Wide backlit LCD display
The front panel of the instrument bears the function keys for the selection of the above-
listed functions (see chapter 4.2). The measured value appears on the wide LCD display
with the indication of the measuring unit and of the enabled functions.
In the lower part of the instrument there are the terminals for the AC analogue output with
3,5 mm coaxial connector and the (USB) ports for the connection of a possible DC 5V
external adapter for power supply without using the internal battery and RS-232 (non-
active output)
In the rear part of the instrument there is a hole for installing the instrument onto a possible
tripod while measuring.

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EN - 5
3. PREPARATION FOR USE
3.1. INITIAL INSPECTIONS
Before shipment, the instrument’s electronics and mechanics have been inspected.
All possible precautions have been taken in order for the instrument to be delivered
without damage.
However, we recommend generally inspecting the instrument in order to detect any
damage suffered during transport. Should you detect any anomalies, immediately contact
the forwarding agent.
Moreover, we recommend checking that the package contains all parts listed in § 10.6.
Should you find any discrepancy, please contact the dealer.
Should it become necessary to return the instrument, please follow the instructions
reported in § 11.
3.2. INSTRUMENT POWER SUPPLY
The instrument is supplied by 4x1.5V alkaline batteries type AA IEC LR06 included in the
package. The battery duration is of approximately 8 hours. When batteries are almost flat,
the symbol “ ” appears on the display, further to the indication “BATTERY LOW”. To
replace the batteries, follow the instructions given in § 9.2.
The instrument may be supplied also by means of the provided external DC 5V supply
connected to the USB interface. It is not necessary to remove the internal battery when
the external power supply is connected. The instrument is provided with an automatic
control which detects the presence of batteries or power supply and monitors the battery
voltage. In case the external power supply is used and supply drops while measuring, the
instrument passes directly to using the batteries, with no measurement interruption.
3.3. CALIBRATION
The instrument complies with the technical specifications reported in this manual. The
instrument performance is guaranteed for 12 months.
3.4. STORAGE
In order to guarantee precise measurements, after a long storage period, in extreme
environmental conditions, wait for the instrument to return to normal conditions (see the
environmental specifications listed in § 10.5)

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EN - 6
4. OPERATING INSTRUCTIONS
4.1. INSTRUMENT DESCRIPTION
4.1.1. FRONT PANEL LEGEND:
1. Microphone
2. ON key
3. OFF key
4. CANCEL key
5. Key to turn on the backlight
6. LCD display
7. ENTER key
8. EXIT key
9. OUTPUT key
10. START/PAUSE key
11. Arrow key for programming
12. Arrow key for programming
13. Arrow key for programming
14. Arrow key for programming
15. SETUP key for programming
Fig. 1: Description of the instrument’s front panel
4.1.2. OUTPUT INTERFACE LEGEND:
1. AC analogue output
2. RS-232 interface (not active)
3. Mini USB interface
Fig. 2: Description of the output interface

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4.2. DESCRIPTION OF FUNCTION KEYS
Key Description
Pressing the ON key allows turning on and internally resetting
the instrument at any time
The OFF key allows turning off the instrument
The CANCEL key allows deleting the saved data from the
instrument’s memory
A
ctivates/deactivates the display’s backlight. Backlight turns off
automatically after 15s
The ENTER key allows entering the internal programming
screens and confirming the selections made
The OUTPUT key allows stopping the measurements and
automatically saving the result in the memory
The START/PAUSE key allows activating or pausing a
measurement
, , ,
The arrow keys allow navigating the programming menu,
increasing/decreasing the parameter values by one unit (press
and hold the keys for fast advance) and adjusting the display
contrast
The SETUP key allows rapidly accessing the programming
menu without passing from the main menu when a
measurement is in progress
4.3. ANALOGUE OUTPUT DESCRIPTION
The instrument is provided with an AC voltage analogue output proportional to the input
signal measured in dB, which can be used to connect a 3.5mm output jack with the
characteristics shown in Fig. 3
Fig. 3: Description of jack for AC analogue output
The proportion between the output and the input signal depends on the measuring range
of the instrument and is shown in the following table:
Gain range Output/input ratio Measuring range [dB]
-10dB 0.316 50~140
0dB 1 40~130
10dB 3.16 30~120
20dB 10 20~110
30dB 31.6 10~100
40dB 100 0~90
The impedance of the AC output signal is 1k. We recommend that the charge resistance
connected to the AC output is at least 100kand that the charge capacity is lower than
200pF. The ratio between the input and the output signal is 1mV / 0.1dB. The max output
voltage is 3.2V.

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4.4. DISPLAY CONTRAST ADJUSTMENT
The instrument allows adjusting the display contract, proceeding as follows:
1. Turn on the instrument by pressing the key. The display shows the following
screen:
Fig. 4: Display contrast adjustment
2. Within 5s, press the arrow keys “ ” and “ ” respectively to decrease or increase the
contrast level of the display. This parameter is shown in the upper right-hand part of the
box “Realtime Analyzer”. Up to 30 contrast levels are possible
4.5. TURNING ON/OFF THE INSTRUMENT
Respect the following instructions when turning on and off the instrument
Press the key to turn on the instrument. The main screen in which the possible
measuring modes are listed is shown on the display. Use the keys “ ” and “ ” for
selecting and confirm with “ ”. If no key is pressed within 5s, the instrument
automatically sets itself to the last mode used
Pressing the key when measuring automatically resets the system and brings the
instrument back to the initial selection menu
Press the key to turn off the instrument. With the instrument turned off, the
instrument’s clock does not stop working thanks to the internal back-up battery. This
battery is continuously recharged when the instrument is measuring and at least 24
hours are necessary for a complete charge. With fully charged back-up battery, the
internal clock is maintained for over 3 months
The measurement results are saved in an internal flash memory and are always
maintained even with no external power supply or with the instrument turned off