4
5
4.1.2. STANDARDS ANSI S3.19-1974 (US) AND
CSA 22.2 (CANADA)
U.S. EPA specifies the NRR as the measure of hearing
protector noise reduction. However, 3M makes no
warranties as to the suitability of the NRR for this
purpose. 3M strongly recommends personal fit testing
of hearing protectors. Research suggests that users
may receive less noise reduction than indicated by
the attenuation label value(s) on the packaging due to
variation in fit, fitting skill, and motivation of the user.
Refer to applicable regulations or guidance on how to
adjust attenuation label values. It is recommended that
the NRR be reduced by 50% to better estimate typical
protection.
Table
ref.
Description
B:A
Headband with foam cushion
B:B
Headband with foam cushion
B:C
Carrier attachment with foam cushion
B:D
Carrier attachment with foam cushion
B:1
Frequency (Hz)
B:2
Mean Attenuation (dB)
B:3
Standard Deviation (dB)
B:4
NRR = Noice Reduction Rating
B:5
CSA Class
(CSA = Canadian Standard Association)
4.1.3. STANDARD AS/NZS 1270:2002
Table
ref.
Description
C:A
Headband with foam cushion
C:B
Headband with foam cushion
C:C
Carrier attachment with foam cushion
C:D
Carrier attachment with foam cushion
C:1
Frequency (Hz)
C:2
Mean Attenuation (dB)
C:3
Standard Deviation (dB)
C:4
Mean minus SD
Table
ref.
Description
C:5
SLC
80
= Sound Level Conversion rating
C:6
Class
C:7
Clamping force (N)
4.1.4. CARRIER DEVICES
These earmuffs should be fitted to and used only with the
carrier devices listed in Table K. These earmuffs were
tested in combination with the carrier devices listed in
table K, and may give different levels of protection if fitted
to different carrier devices.
Explanation of the carrier attachment table:
Table
ref.
Description
K:A
Compatible carrier devices
K:1
Manufacturer
K:2
Model
K:3
Attachment code
K:4
Head size: S = small, M = medium, L =
large
When selecting accessories to respiratory personal
protective equipment, such as carrier mounted hearing
protection, please consult the NIOSH approval label or
consult 3M Technical Services for approved
configurations.
5. OVERVIEW
5.1. COMPONENTS
MT13H220A, MT13H221A, MT13H222A, MT13H223A
F:1 Headband (stainless steel, PVC, PA)
F:2 Headband wire (stainless steel)
F:3 Two-point fastener (POM)
F:4 Cushion (PVC foil and PUR foam)
F:5 Foam liner (PUR foam)
F:6 Cup (ABS)
F:7 Level dependent microphone for ambient listening
(PUR foam)
F:8 Latch (PA)
F:9 On/Off/Mode button (TPE)
F:10 [+] button (TPE)
F:11 [–] button (TPE)
MT13H220P3E, MT13H221P3E
F:12 Cup supporting arm (stainless steel)
EN
