Cal. Code Regs. Tit. 13, § 1028 - Performance Requirements
(a) Siren Functions. Electronic sirens shall
have a wail function and may also have manual and yelp functions. No other
function is permitted on sirens sold after January 1, 1982, except for voice
communication. Sirens shall meet the following requirements in addition to the
sound levels specified in Table I:
(1) Wail.
The wail function shall have an automatic undulating pitch rate of not less
than 10 nor more than 30 oscillations per minute. The sound level shall not
drop more than 10 dB(A) below the required values in Table I during the lowest
portion of any cycle.
(2) Manual.
Electronic sirens manufactured after January 1, 1982, which include a manual
function shall use the vehicle horn ring or any other manual momentary contact
switch to allow the vehicle operator to switch between the wail and yelp
functions, to momentarily override the descending sound pattern of the
automatic cycle when the control is set at "wail," or to produce a
manually-cycled wail when the control is set at "manual."
(3) Yelp. The yelp function shall have an
automatic undulating pitch rate of not less than 150 nor more than 250
oscillations per minute, except for sirens sold prior to July 1,
1980.
(b) Sound Level
Output. Two classes of sirens, A and B, are established based on the A-weighted
sound level output measured at the angles specified in Table I. The sound level
measurements of electronic sirens shall be started immediately after the siren
has been operated for one minute. A deviation of 1 dB(A) below the specified
value shall be allowed at any three of the eleven test points.Table I. Minimum
A-Weighted Sound Level at 3.0 m (9.8 ft)
Rotation deg left and right from axis |
Sound Level, dB(A) Class A |
Class B |
0 |
120 |
115 |
10 |
119 |
114 |
20 |
118 |
113 |
30 |
117 |
112 |
40 |
115 |
110 |
50 |
113 |
108 |
(c)
Siren Classification. The A or B overall classification of a siren shall be the
class of the lowest performing function incorporated in the siren. The reported
sound level for each test point under manual operation shall be the
steady-state level reached during continuous activation. The reported sound
level for the wail and yelp functions at each test point shall be the average
of the levels reached by five consecutive major peaks.
(d) Frequency Requirements. The maximum sound
level in the axis of the siren shall occur in either the 1000- or the 2000-Hz
octave bands for all functions.
(e)
Electronic Siren Wattage. The wattage drawn by speakers of electronic sirens
shall not exceed the following requirements when tested at the voltages
specified in Section
1027(b) of this
article. The voltage leads of the wattmeter shall be connected to the speaker
terminals on the amplifier, and readings shall be taken in the order of manual,
wail, and yelp.
(1) At the voltage specified
for the sound level tests, the measured wattage after 1 min and before 3 min of
operation shall not exceed the rating of the driver.
(2) At the voltage specified for wattage
tests, the wattage shall not exceed 105% of the rating of the driver when
measured after 10 min of operation.
(3) The wattage recorded for wail and yelp
shall be the mathematical average of the high and low readings of five
continuous cycles as the signal varies.
Notes
Note: Authority cited: Section 26103, Vehicle Code. Reference: Sections 26103 and 26104, Vehicle Code.
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