IPC-TM-650 EN 2022 试验方法-- - 第648页
5.4.2 Precondition the ch amb er and its contents at: 30 ± 1 °C [86 ± 2 °F] and 95 ± 2% relative humidity for at least four hours. 5.4.3 Inoculate the test and c ontrol items with t he mixed fungus spore suspension (5.1.…
strips of filter paper on the surface of mineral salts agar. (Min-
eral salt agar is identical to mineral salt solution, but contains
an additional 15.0 g of agar per liter.)
5.1.6
The stock cultures may not be kept longer than four
months at 6 ± 4 °C [43 ± 7 °F] at which time subcultures shall
be made and new stocks shall be selected from the subcul-
tures.
5.1.7
If genetic or physiological changes occur in the cul-
ture, obtain new cultures in accordance with 5.1.4. Sub-
cultures used for preparing new stock cultures or the spore
suspension shall be incubated at 30 °C ± 1 °C [86 °F ± 2 °F]
for at least nine days.
5.1.8 Prepartion of Spore Suspension
5.1.8.1
Pour 10 ml of a sterile solution containing about
0.05 g/L of a nontoxic wetting agent such as sodium dioctyl
sulfosuccinate or sodium lauryl sulphate into one culture of
each fungus.
5.1.8.2
Use a sterile platinum or nichrome inoculating wire
to free the fungus from the culture medium by gently scraping
the surface growth of the agar from the culture of the medium.
5.1.8.3
Pour the spore suspension into a sterile 125-ml
glass-stoppered Erlenmeyer flask containing 45 ml of sterile
water and 50 to 75 solid glass beads, 5.0 mm [0.197 in] in
diameter.
5.1.8.4
Shake the flask vigorously to liberate the spores
from the fruiting bodies and to break the spore clumps.
5.1.8.5
Filter the dispersed fungal spore suspension through
a 6 mm layer of glass wool contained in a glass funnel and
collect into a sterile flask. This process should remove large
mycelial fragments and clumps of agar which could interfere
with the spraying process.
5.1.8.6
Centrifuge the filtered spore suspension and discard
the supernatant liquid.
5.1.8.7
Resuspend the residue in 50 ml of sterile water and
centrifuge.
5.1.8.8
Wash the spores obtained from each of the fungi in
this manner three times.
5.1.8.9
Dilute the final washed suspension with sterile
mineral-salt solution such that the resultant spore suspension
contains 1,000,000 ± 200,000 spores per ml as determined
with a colony counter.
5.1.9
Repeat the steps in 5.1.8 for each organism used in
the test and blend equal volumes of the resultant spore sus-
pension to obtain the final mixed spore suspension. The spore
suspension may be prepared fresh each day or may be held
at 6 ± 4 °C [43 ± 7 °F] for not more than seven days.
5.2 Viability of Inoculum Control
With each daily group
of tests, place one piece of sterilized filter paper, 2.5 cm [1.0
in] square, on hardened mineral-salt agar in three separate
Petri dishes. Inoculate these dishes with the spore suspension
by spraying the suspension from a sterilized atomizer until
initiation of droplet coalescence. Incubate these at 30 ± 1 °C
[86 ± 2 °F] at a relative humidity not less than 85% and exam-
ine them after seven days of incubation. There shall be copi-
ous growth on all three of the filter paper control specimens.
Absence of such growth requires repetition of the test.
5.3 Control Items
5.3.1
In addition to the viability of inoculum control, known
susceptible substrates shall be inoculated along with the test
item to insure that proper conditions are present in the incu-
bation chamber to promote fungus growth.
5.3.2
The control items shall consist of 284.5 g/m
2
[8.25-oz]
bleached, scoured, 5 cm [2 in] long cotton duck strips, that
have been dipped into a solution containing 10% glycerol,
0.1% potassium dihydrogen orthophosphate (KH
2
PO
4
), 0.1%
ammonium nitrate (NH
4
NO
3
), 0.025% magnesium sulfate
(MgSO
4
7H
2
O), and 0.05% yeast extract (pH 5.3), from which
the excess liquid has been removed.
5.3.3
The strips should be hung to air dry before being
inoculated and placed into the chamber.
5.4 Inoculation of Test and Control Item
5.4.1
Mount the test and control items on suitable fixtures or
suspend from hangers. No cleaning of the test item shall be
permitted for 72 hours prior to the beginning of the fungus
test. Equipment handling prior to and during the fungus test
shall be accomplished without contamination of the equip-
ment.
Number
2.6.1
Subject
Fungus Resistance of Printed Board Materials
Date
03/07
Revision
G
IPC-TM-650
Page
2
of
3
5.4.2
Precondition the chamber and its contents at: 30 ± 1
°C [86 ± 2 °F] and 95 ± 2% relative humidity for at least four
hours.
5.4.3
Inoculate the test and control items with the mixed
fungus spore suspension (5.1.4) by spraying it on and into the
test and control items (if not hermetically sealed) in the form of
a fine mist from a previously sterilized atomizer or nebulizer. In
spraying the test and control items, care should be taken to
spray all surfaces that are exposed during use or mainte-
nance. If the surfaces are nonwetting, spray until initiation of
droplet coalescence. Incubation is to be started immediately
following the inoculation.
5.5 Test Incubation of Test Items
5.5.1
Incubate test items at an air temperature of 30 ± 1 °C
[86 ± 2 °F] at 85% minimum relative humidity.
5.5.2
After seven days, inspect the growth on the control
items to be assured that the environmental conditions are
suitable for growth. If inspection reveals that the environmen-
tal conditions are unsuitable for growth, the entire test shall be
repeated.
5.5.3
If the control items show satisfactory fungus growth,
continue the test for a period of 28 days from the time of
inoculation, or as specified.
5.6 Evaluation
5.6.
Report those specimens which were found to be nutri-
ent to fungus growth.
5.6.2
Corrosion should be noted separately from the fungus
test results.
6 Notes
6.1 Source for Microorganisms
6.1.1
ATC
P.O. Box 1549
Manassas, VA 20108
(703) 365-2700
www.atcc.org
6.2 Secondary Sources for Microorganisms
6.2.1
Pioneering Research Division
U.S. Army Natick Laboratories
Natick, Massachusetts 01760
6.2.2
USDA, 1815 North University St., Peoria, IL 61604
6.3
After evaluation, the materials and the test chamber
must be decontaminated by exposure on all sides to ultra-
violet rays (360 nm) for a minimum of two hours, or sprayed
with a solution of 1:750 zephiran chloride solution. (One part
zephiran chloride to 750 parts distilled water.)
6.4 Safety
Observe all appropriate precautions on MSDS
for chemicals involved in this test method.
6.5 Nutrient Agar
Covered petri dishes containing nutrient
agar are considered to have the desired humidity. Covers on
larger dishes containing nutrient agar may need to be sealed
with masking tape.
Number
2.6.1
Subject
Fungus Resistance of Printed Board Materials
Date
03/07
Revision
G
IPC-TM-650
Page
3
of
3
Steady State Test
Humidity—Temperature Cycling Test
Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only
and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this
material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.
Page 1 of 3
r
ASSOCIATION
CONNECTING
/
ELECTRONICS
INDUSTRIES
2215
Sanders
Road
Northbrook,
IL
60062-6135
IPC-TM-650
TEST
METHODS
MANUAL
Number
3.5
Subject
Humidity,
Connectors
Date
Revision
7/75
A
Originating
Task
Group
N/A
1
.0
Scope
1.1
To
determine
the
effect
on
the
connector
of
prolonged
exposure
to
conditions
of
high
humidity
at
various
tempera¬
tures.
Two
conditions
of
test
are
provided
as
follows:
Used
to
evaluate
the
hydroscopic
nature
of
insulating
materials
as
evidenced
by
deteriorated
physical
properties
(dimensions,
mechanical
strength,
etc.)
or
degraded
electrical
properties
(e.g.,
insulation
resistance).
Used
to
evaluate
the
effectiveness
of
seals
and
gaskets
in
the
presence
of
a
pres¬
sure
differential
induced
by
varying
temperatures;
the
corro¬
sion
resistance
of
metals
and
finishes
exposed
to
alternate
periods
of
condensation
and
drying;
and
the
hydroscopic
nature
of
insulating
materials,
with
any
degradation
acceler¬
ated
by
the
“breathing”
action
imposed
by
varying
tempera¬
tures.
Optional
exposures
to
sub-freezing
temperatures
and
to
mechanical
vibration
exaggerate
any
structural
deterioration
of
insulating
materials.
2
.0
Reference
Documents
2.1
Information
in
this
section
is
intended
to
parallel
the
test
method
described
in
EIA-RS-364/TP-31
.
3
.0
Test
Specimen
3.1
A
connector
(plug
and
receptacle)
complete
with
appli¬
cable
guide,
keying,
and
engaging
hardware
or
a
card-
edge
receptacle
and
mating
printed
circuit
board
(if
required
by
the
individual
connector
specification).
The
connector
or
recep¬
tacle
shall
be
mated
or
unmated
as
specified
in
the
individual
connector
specification.
3.2
Neither
the
plug
nor
the
receptacle
shall
be
mounted
or
terminated
during
the
test,
unless
such
mounting
(or
termina¬
tion)
is
necessary
(1)
to
insure
the
mechanical
integrity
of
the
component,
(2)
to
measure
the
specified
electrical
character¬
istics),
(3)
was
a
requirement
of
previously
imposed
environ¬
mental
or
functional
tests.
3.3
Printed
circuit
boards
may
be
conformal
coated
to
reduce
the
effect
of
their
deterioration
due
to
moisture
on
the
connector
characteristic(s)
under
evaluation.
The
coating
shall
not
be
applied
to
any
portion
of
the
connector
under
test.
3.4
The
plug,
receptacle
or
mated
connector
shall
be
sus¬
pended
or
supported
within
the
test
chamber
in
a
normal
(or
typical
mounting
attitude
using
non-corrosive
material
(e.g.,
plastic,
corrosion
resisting
steel,
etc.)).
The
technique
utilized
shall
not
impede
the
flow
of
circulating
air
over
and
around
the
test
specimen.
4
.0
Apparatus
4.1
A
temperature-humidity
chamber
capable
of
maintaining
dry
bulb
temperatures
from
+
25℃
to
+
65℃
within
土
2
℃
of
the
set
temperatures
and
relative
humidity
greater
than
90%
during
ascending
or
constant
temperature
operation
and
greater
than
80%
during
descending
temperature
operation.
Circulation
of
air
within
the
chamber
shall
be
at
a
minimum
cubic
rate
equivalent
to
five
times
of
non-corrosive
material
and
shall
prevent
the
dripping
of
condensate
onto
the
test
specimen.
4.2
A
temperature
chamber,
when
required,
capable
of
maintaining
a
temperature
of
-10℃
+0,
-4℃.
4.3
A
temperature
measuring
device,
when
required,
of
suit¬
able
range
for
the
specified
test
condition.
4.4
A
vibration
system,
when
required,
capable
of
producing
approximately
simple
harmonic
motion
at
a
double
amplitude
of
0.60
inch
in
the
frequency
range
from
1
0
to
55
Hz.
5
.0
Procedure
5.1
Pre-Conditioning
The
test
specimen
shall
be
condi¬
tioned
in
a
dry
oven
at
a
temperature
of
50℃
±5℃
for
a
mini¬
mum
period
of
twenty-four
hours.
After
stabilization
at
room
ambient
conditions,
the
test
specimen
shall
be
subjected
to
the
pre-test
measurements
specified
in
the
individual
connec¬
tor
specification.
5.2
Steady-State
Test
5.2.1
The
test
specimen
shall
be
suspended
within
the
humidity
chamber
and
subjected
to
a
relative
humidity
of
90-95%
at
a
temperature
of
40℃
土
2
℃
for
a
period
of
time
corresponding
to
one
of
the
test
conditions
shown
in
Table
1
.
Unless
otherwise
specified,
Test
Condition
D
shall
apply.