HT instruments HT157 - Manual (Page 5)

HT155 - HT157
EN - 3
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
 Always 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.