G.R.A.S. 45CA User Manual

G.R.A.S. SOUND & VIBRATION
Page 5
Hearing-Protector Test Fixture Type 45CA
1.2 WhichCongurationtoUse
Table1showswhateachofthethreecongurationscanbeusedfor:
ISO4869-3Congurationwith1"(or½"*)Microphone*
Pressuremicrophones,bothexternallyandpolarizedtypesavailable.
Thecongurationisapplicablefortestingoutside-the-eardevices;i.e.
• For measuring the insertion loss of ear muffs
• For testing the sound quality of earphones
IEC60318CongurationwithEarSimulatorRA0039
RA0039 simulates an ear and is used for measuring the sound pressure at the ear entrance
point (EEP).
RA0039mustbeconguredwitha½"microphone,externallypolarizedorprepolarized.
IEC60711CongurationwithEarSimulatorRA0045
Theseearsimulatorsareforusewithapinnasimulator(articalear)formeasuringthesound
pressure at the eardrum (DRP), thus also applicable for ear inserts. RA0045 available both in
externallypolarizedorprepolarizedversions.
Standard ISO 4869-3 * IEC 60318 IEC 60711
Test Setup
(G.R.A.S.equip-
menttouse)
Pressure Microphone
– 1" 40EN or
– ½" 40AP/40AD
Ear Simulator RA0039
with ½"microphone:
– 40AG (ext. pol.) or
– 40AO (pre-pol.)
Ear Simulator
– RA0045 (ext. pol.) or
– RA0045-S1 (pre-pol.)
Device to test
Ear muffs
+ + +
Earplugs
- - +
Headphones
+ + +
Earphones
- - +
Hearing-aids
- - +
080016
*ThecongurationwillbeinconformitywithISO4869-3onlyif1" Microphone Type 40EN is used.
Table 1 Providing an overview: Which conguration to use

G.R.A.S. 45CA Specifications

General

Brand	G.R.A.S.
Model	45CA
Category	Protection Device
Language	English