AS ISO 9533:2020 – Earth-moving machinery — Machine-mounted audible travel alarms and forward horns -Test methods and performance criteria.
5 Test environment
5.1 Test area
The test area shall consist ol a tree tield above a harii reFlecting plane no rougner tnan non-porous asphalt. The test area bordered by the machine and the microphone shall also consist ofa flat, horizontal surface or surface sloping downwards away from the centre of the test area. No reflective obects such as buildings should be within 30 m of the microphone or the machine being measured.
The test technician or test equipment shall be > 2 m from the sound-measuring microphone during exterior location measurements.
NOTE For further details giving the recommended test area configuration, see ISO 3744 and ISO 6393.
5.2 Background noise
The ambient A-weighted sound pressure level due to sources other than the earthmovlng machinery under test, including wind effects, shall be at least 10 dB lower than the lowest measurement of interest.
5.3 Climatic conditions
Measurements shall not be carried out when precipitation. e.g. rain, snow or sleet, is falling or when the ground is snow-covered. Tue ambient temperature shall be within a temperature range —10°C to +35°C.
NOTE For further details giving recommended climatic conditions, see ISO 6393.
5.4 Wind
The average wind speed at the test site shall he less than H rn/s.
Wind speeds at each measurement location due to machine operation should also be below 8 rn/s. For measurement locations where wind speeds are above this value, sound measuring equipment designed for high wind applications should be used.
6 Machine preparation
6.1 Voltage
Verify that the alarm activation voltage to the audible travel alarm(s) or forward horn Is within the nominal operating voltage specified by the manufacturer of the travel warning alarm(s) or forward horn.
6.2 Engine and transmission
6.2.1 General
tinder prevailing conditions, the machine shall be at a stabilized temperature [or all its primary power systems at maximum governor engine speed (high idle).
6.2.2 CoolIng system fan speed(s)
If the powertraln or hydraulic system or systems of the machine are fitted with an adjustable fan or tans, they shall operate during the test at maximum achievable fan speed at the engine speed as specified in Clause 7.
If equipped with an electric fan or fans, these shall be off when taking sound pressure measurements with the engine off.
6.3 Equipment and attachments
For testing, the equipment and attachnwnt(s) for the most typical machine configuration as specified by the machine manufacturer shall be installed and in the carry position for travelling (see ISO 5006). The attachment position shall also be as specified by the manufacturer.
6.4 Operator station
6.4.1 Heating, ventilation and air-conditioning system
lithe operator station is equipped with a heating, ventilation and air-conditioning (HVAC) system or systems, these shall be set to mid-setting during all tests, defined below. The ventilation ducts shall be open with the air flow directed out but away from the operator.
— For an Off/Low/High system, at mid-setting the HVAC fan setting(s) will be at “High”.
— For an Off/Position 1/Position 2/Position 3 system, the mid-setting will be Position 2.
— For a continuously variable system, the mid-setting is at or above 50% of the maximum fan speed.
lithe HVAC system consists of multiple systems, e.g. separate upper and lower controls, all systems
shall be set to mid-setting.
NOTE For further details on Ian speed and fan settings. see ISO 6393.
6.4.2 Operator size and location
For testing at the location of the operator, an operator should be selected whose physical dimensions are as close as possible to a medium operator, and within the limits for a small to a large operator, as defined in ISO 3411.
The seat shall be positioned in the mid-position for fore and aft and for vertical height, if adjustment is provided. The seat and head rest, if present, shall be adjusted to accommodate the operator and shall remain consistent during the test series.
6.4.3 Additional considerations
Other considerations for the operator station include eliminating non-typical machine noise such as radios and monitor alarms. For cab units, all windows and doors shall be closed. Cab interior materials and seals should be typical of the machine type and family.
7 Test procedures
7.1 General
Measurements shall be taken and recorded at the alarm and horn Lest measurement locations shown in Figure 1 and in accordance with Table 1.