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LUBRICATION TESTS 1. INTRODUCTION - Stellenbosch...
Transcript of LUBRICATION TESTS 1. INTRODUCTION - Stellenbosch...
LUBRICATION TESTS
1. INTRODUCTION
This study concerns the evaluation of possible lubricants that are suitable for the
mechanical part of Safety and Arming Devices (SADs). A series of tests were
conducted with a DIM in a centrifuge to evaluate its performance with different
lubricants within the specified temperature range.
First some background is given on the various lubricant properties that need to be
evaluated. Although the hardware is similar, the working conditions that a SAD is
subjected to are somewhat different than that of small general-purpose mechanical
devices. Therefore the emphasis with regard to lubricant properties was on the
properties that are relevant to SADs, as there are numerous parameters that do not
have a significant influence for this particular application. The importance of various
lubrication aspects are discussed briefly and evaluated with regard to their
applicability to a SAD.
2. BACKGROUND
Numerous oil brands are manufactured around the world, each with its own unique
and specialized characteristics. The majority of oils and greases are suitable for use
between ambient temperature and up to temperatures of approximately 120°C as most
mechanical equipment operate in an ambient environment with some additional
temperature increase due to friction or combustion. A good example is probably the
internal combustion engine found in virtually all land vehicles and sea going vessels.
When dealing with lubrication in the world of aviation, the same basics apply but with
increased specifications as the reliability of mechanical components are much more
critical in the air than on the ground. Therefore almost all lubricants intended for use
in aircraft are of exceptional quality. Aeroshell Fluid 12, as currently used for
lubrication of the mechanical SADs, is a good example of such a lubricant.
Laboratory and field tests are usually performed on lubricants to arrive at the
optimum balance between cost, performance and additives. This performance refers
to the life span of a lubricant evaluated at a given maximum temperature it will be
subjected to in its service life. In aviation applications, another criterion, low
temperature performance, plays a significant role. The main reason being that the
viscosities of virtually all lubricants increase dramatically at temperatures below 0°C.
For Aeroshell Fluid 12 this increase in viscosity is more than 130 fold from +40°C to
-40°C. This results in frictional forces that are drastically higher at subzero
temperatures compared with ambient conditions.
The arming time of a SAD is a critical factor when activated and this is directly
dependent on the accurate repeatable mechanical operation of such a device under all
specified conditions e.g. temperature. This is where the viscosity properties of a
lubricant could play a vital role in the performance of a SAD as it determines the
moving resistance of the mechanical timing components.
3. EVALUATION CRITERIA
In this section the most relevant aspects regarding the selection of a lubricant for use
in devices like mechanical SADs are discussed. It should be noted that even though
these criteria allow theoretical selection of lubricants, the optimum result could only
be obtained through thorough testing under controlled conditions. The following
criteria were used to select commercially available lubricants, with a short discussion
of each on its applicability to SADs.
Oil, grease or solid lubricant: Grease is a base lubricating oil suspended in a
thickener to which some additives are usually added. The consistency range from
solid to soft or semi-fluid. In Table 1 the advantages of each are listed.
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Table 1: Advantages of different types of lubricants
Advantages of oil
1. Heat dissipation is possible when oil is circulated 2. Contaminants can be captured with a filter 3. Higher rotational speeds are possible compared to grease 4. Less heat is generated between frictional surfaces due to lower viscosity
Advantages of grease
1. No circulation system ⇒ reduced design complexity 2. Lifetime lubrication possible ⇒ lower maintenance 3. Simpler seal design and less leakage due to thickener 4. Sealing improved by ‘collaring’ of excess grease 5. High revolutions at low bearing temperatures possible after running-in period with
metered grease quantities
Advantages of solid lubricants
1. Extremely low starting torque (torque ripple) 2. Usually exceed -200°C to 200°C temperature range 3. Lubricant permanently fixed to surfaces but specific design, bearing disassembly
and baking usually necessary 6. No fluid ⇒ no viscosity changes
Table 1 is applicable to most applications of lubricants in the industry and can be
used for deciding between the use of either grease or oil in the design stage.
However, SADs only need to reliably operate once for a very short duration at the
end of its possible 10-year life span. From Table 1 it is evident that oil, grease or
solid lubricant may be suitable for use in a SAD. One must bear in mind that the
viscosity of greases is usually given for to the base lubrication oil and not the
product as a whole that includes the stiffeners and additives. It is thus not
possible to determine the thickness of grease from a standard product data sheet
at, for example, the -40°C lower temperature limit as required. This might
significantly influence the timing properties of a SAD across the required
temperature range. Running in of the devices can be done to force the majority of
the grease away from the rolling bearings. However, the long storage times and
possible vibration these devices can be subjected to, may cause the grease to
migrate, resulting in a device that need to be ‘run in’ again.
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In the industry, oils are used in small delicate mechanisms such as precision
instruments like watches. On sliding parts, greases are more suitable as their
movements are mainly restricted to one-dimension. Light, low-shear greases are
used effectively for low-power devices such as appliance timer motors. Some of
these greases are semi-fluids, which reduce their noise damping qualities
considerably. Again, in subzero conditions these properties may still change
considerably.
Solid lubricants are well suited for space applications where low out-gassing of
lubricants is crucial. The temperature range at which they are effective is also
extreme. Their main disadvantage is the challenge involved to apply these layers,
as the baking process usually requires temperatures in excess of 180°C, which can
destroy some materials. Therefore, the use of solid lubricants has to be taken into
account at the design stages. However, there are solid lubricants that do not need
any baking or disassembly of bearings and this may give satisfactory results
despite the fact that they offer short wear life.
Grease thickeners: These can be divided into soap and no-soap thickeners. The
soap thickeners are made from fatty acids, e.g. palm, olive and sunflower oil,
where the non-soap thickeners are made up of materials such as clay (bentonite),
silica gel and carbon black. On average, thickeners make up 3% to 15% of grease.
The most useful aspect of thickeners with respect to SADs is the useful lifetime
they are usually associated with. These include thickeners such as sodium
complex, polyurea and plastic (PE, PTFE, FEP) that are used in most long-term
greases. The resulting grease thickness can be measured with a penetrometer
according to ISO 2137 and classified to NGLI classes according to DIN 51 818, as
shown in Table 2:
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Table 2: Classification of grease thickness
NGLI class Structure General application
000 00 0
Fluid Almost fluid Extremely soft
Primarily for gear lubrication
1 21 3
Very soft Soft Moderate
Lubrication for plain and rolling bearings
4 5 6
Stiff Very stiff Extremely stiff
Sealing and barrier greases for labyrinth seals and taps
Additives: Additives are normally used in a lubricant, oil or grease, to enhance
certain properties to make it more suitable for specific operating conditions. The
general rule is to only use an additive if it is necessary the reason being that they
increase production costs. Table 3 gives the basic qualities that can be improved
by additives.
Table 3: Added qualities due to additives 2Additive Purpose
Extreme pressure additive
Increase load carrying capacity, protection against micro-welding
Anti-wear additives Reduction of wear in the mixed friction regime
Friction modifiers Reduction of friction losses, impede stick-slip and noises, neutralization of acid aging products
Corrosion inhibitors Protection against corrosion attack on metallic materials
Oxidation inhibitors Retard oxidation, reduction of surface layer and sludge formation
Solid lubricants Improvement of load carrying capacity, reduction of stick-slip
Tackifiers Improvement of lubricant adhesion to surfaces
1 NGLI grade 2 is most commonly used
2 Information obtained from Klüber Lubrication, P.O. Box 11461, Randhart, Alberton 1457,
Tel: 011 908 2457
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Suitable additives can be selected only once suitable lubricating oil has been
decided upon, as they are not always compatible. A SAD needs to perform only
once which may only necessitate additives that reduce oxidation, corrosion and
stick-slip (low starting friction).
Viscosity: The viscosity of a fluid describes its ability to resist flow. This is one
of the key parameters of an oil specification. Due to the normal decrease in
viscosity with increase in temperature, viscosity improvers are often added to
reduce this effect.
Viscosity Index: This index is a dimensionless parameter that is commonly used
to give an indication of the tempo at which viscosity increase with temperature for
a specific fluid. The Viscosity Index (V.I.) is defined in the ASTM D 2270
standard and was originally intended to provide a means of comparison between
oils with viscosity improvers and oils without. The V.I. value gives an indication
of the difference in viscosity of a lubricant between 38°C and 99°C, and is
therefore not applicable to temperatures below zero. Thus, for comparison
purposes, the V.I. value only gives a rough indication of the increase in viscosity
in subzero conditions.
Lubricity: The lubricity of a lubricant is the extent to which it reduces the
coefficient of friction between two solids.
Volatility: This describes the evaporation possibility of a lubricant. The more
volatile a liquid, the lower its boiling point and also the higher its flammability.
Flash point: This is the temperature at which a lubricant spontaneously ignites. It
is always safe to keep temperatures well below this value.
High/low temperature capability: Some lubricants are only usable within a very
limited temperature range. When this range is significant, it is necessary to verify
that all critical properties are within acceptable limits, from the lowest to highest
temperature.
Wear-prevention ability: This is a particularly important characteristic that play
a large role with sliding and turning parts at their contact surfaces when no
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hydrodynamic film is present to separate surfaces. Lubricity and extreme pressure
additives help prevent the microscopic roughness of contacting surfaces from
damage. The wear prevention ability of a lubricant can greatly reduce surface
damage caused by vibration such as SADs may be subjected to.
Static friction: The static friction factor is used to determine the force needed to
initiate sliding between two surfaces. In the case of a SAD one would try to keep
this value as constant as possible over the whole temperature range. This friction
is sometimes also referred to as ‘stick-slip motion’, especially when reciprocating
parts are involved.
Migration (spreading): The ability of a lubricant to stay in one place after
application is very important when dealing with lifetime lubrication. Silicone oils
are known for their ‘ability’ to migrate. However, the dipping of SADs in such a
lubricant should be adequate to ensure lubrication for life. A common practice is
to produce light greases of oils that migrate easily but then the temperature
characteristics are also influenced.
Material Compatibility: Compatibility with all materials that a lubricant may be
in contact with should be checked. The lubricant could affect material properties
(e.g. certain plastics) extremely negatively and may also destroy the lubricant.
Aging (gumming): Aging is of particular interest with lifetime lubrication where
virtually no degradation of the lubricant can be allowed for. This is a critical
property when used in SADs and necessitate a chemically stable (preferably inert)
lubricant. Virtually all lubricants used in the aviation industry are very stable and
have a low tendency to gum after prolonged use.
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4. AVAILABLE LUBRICANTS
Two classes of oil lubricants are available for lubrication. The first is natural oils that
are found in nature and include mineral oils, which are widely used in machinery all
over the world. Although mineral oils are the most affordable, they are often
aggressive to materials they come in contact with and also tend to age.
The second class includes all synthetically produced oils. There is quite a large range
of these oils commercially available and the list is constantly growing. The general
advantage of synthetic lubricants is that they are chemically more stable than their
traditional natural counterparts. This make them more suitable for use in applications
where degradation due to reaction between the lubricant and lubricated surfaces is
critical, especially in areas where lifetime lubrication is necessary. In Figure 1 the
main categories of synthetic oils and their associated properties like viscosity and
compatibility, are shown.
The top part of Figure 1 shows the temperature vs. viscosity ranges that the different
types of synthetic oils cover. It is important to note that the axis scales are neither
linear nor logarithmic. The bottom part of Figure 1 shows the most relevant material
compatibility and also the solvents. From Figure 1 it seems that silicone oils are
superior in compatibility, temperature range and viscosity index.
In Figure 2 the temperature ranges for the different types of lubricants are
summarized.
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Figure 1: Synthetic oil viscosity and compatibility chart
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Figure 2: Lubrication temperature ranges (from Nye, www.nyelubricants.com).
5. LUBRICANTS THAT MAY BE SUITABLE FOR USE IN
SADS
The following are the lubricants investigated which may be suitable for use in SADs
sorted according to lubricant oil type.
Synthetic hydrocarbon:
1. Aeroshell Fluid 12 (lubricant currently used)
2. Anderol 401 D
Silicone:
1. Baysilone fluid M 10
2. Baysilone fluid M 20
3. Baysilone fluid M 100
4. Baysilone fluid M 1000
PAO (Polyalphaolefin):
1. NYE oil 132B
PFPE (Perfloropolyether):
1. Krytox 143AA
2. Krytox 143AZ
3. Krytox GPL 105 (grease)
4. NYE uniflor 8910
5. NYE uniflor 8920
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Figure 3: Viscosity as a function of Temperature. Logarithmic scale for viscosity axis
1
10
100
1000
10000
-50 -30 -10 10 30 50 70 90
Temperature [deg C]
Vis
cosi
ty [m
m^2
/s]
Aeroshell fluid 12 NYE uniflor 8910 NYE uniflor 8920 NYE synth oil 132 Krytox GPL 105 Krytox 143AAKrytox 143AZ GE M10 GE M20 GE M100 GE M1000
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
-50 -30 -10 10 30 50 70 90
Temperature [Deg C]
Visc
osity
[mm
^2/s
]
Aeroshell fluid 12 NYE uniflor 8910 NYE uniflor 8920 NYE synth oil 132 Krytox GPL 105 Krytox 143AAKrytox 143AZ GE M10 GE M20 GE M100 GE M1000
Figure 4: Viscosity as a function of Temperature. Linear scale for viscosity axis
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In Figures 3 and 4 the viscosity as a function of temperature are shown for the above-
mentioned oils. Anderol 401 D was excluded in these figures as it conforms to the
same specification as Aeroshell Fluid 12. In Figure 3 a logarithmic scale is used
whilst a linear scale is used in Figure 4 for clarity in the higher and lower temperature
ranges respectively.
6. SPECIFIC LUBRICANT PROPERTIES
6.1. AEROSHELL FLUID 12
AeroShell Fluid 12 is currently used in lubricated SADs and conforms to MIL-PRF-
6085D with heading: LUBRICATING OIL: INSTRUMENT, AIRCRAFT, LOW
VOLATILITY. This is a high quality, synthetic hydrocarbon oil developed for use in
the aviation industry.
Table 4: Properties of Aeroshell Fluid 12
Fluid Property Typical value Units
Pour point < -60 °C
Flash Point 220 °C
Density @ 25°C 925 Kg/m3
Viscosity @ 25°C 18 Mm2/s
Distributor:
Shell SA (Pty) Ltd
P.O. Box 2231
Cape Town
8000
Tel: (021) 408 8911
Orders: 0800 021 021
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6.2. ANDEROL 401 D
This is a synthetic oil with a Diester used for the base fluid. It conforms to MIL-L-
6085 specifications. Anderol 401 D is intended for use as lubricant in miniature
bearings that can be sealed for life.
Table 5: Properties of Anderol 401 D
Fluid Property Typical value Units
Pour point -65 °C
Flash Point 225 °C
Density @ 15.6 °C 930 kg/m3
Viscosity @ 25°C Not given mm2/s
Distributor:
Tenneco Chemicals
6.3. BAYSILONE FLUID SILICONE OIL
Baysilone Fluid is a pure silicone oil. This product is available in a wide range of
viscosities (3 – 2 000 000 mm2/s) other than that specified at 25 oC. One of the key
advantages of this product is its chemical inertness. It is successfully used in
precision instruments as a lubricant in the industry and also possesses good dielectric
characteristics. The specific properties for the various oils are listed in the respective
tables.
Manufacturer:
GE Silicones
USA
(Silicone manufacturing plant is located in The Netherlands.)
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Distributor:
Silicones & Technical Products CC
P.O. Box 547
Paardeneiland
7420
South Africa
Tel: (021) 511 2151
6.3.1. Baysilone Fluid M 10
Table 6: Properties of Baysilone Fluid M 10
Fluid Property Typical value Units
Pour point -90 °C
Flash Point 170 °C
Density @ 25 °C 940 kg/m3
Viscosity @ 25 °C 10 mm2/s
6.3.2. Baysilone Fluid M 20
Table 7: Properties of Baysilone Fluid M 20
Fluid Property Typical value Units
Pour point -70 °C
Flash Point 240 °C
Density @ 25 °C 950 kg/m3
Viscosity @ 25 °C 20 mm2/s
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6.3.3. Baysilone Fluid M 100
Table 8: Properties of Baysilone Fluid M 100
Fluid Property Typical value Units
Pour point -50 °C
Flash Point 300 °C
Density @ 25 °C 970 kg/m3
Viscosity @ 25 °C 100 mm2/s
6.3.4. Baysilone Fluid M 1000
Table 9: Properties of Baysilone Fluid M 1000
Fluid Property Typical value Units
Pour point -50 °C
Flash Point 320 °C
Density @ 25 °C 970 kg/m3
Viscosity @ 25 °C 1000 mm2/s
6.4. NYE OIL 132B
This lubricant conforms to the military specification MIL-DTL-53131A (GRADE 4)
(except that it is not ultra-filtered) with heading:
LUBRICATING OIL, PRESCISION ROLLING ELEMENT BEARING,
POLYALPHAOLEFIN BASED.
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Table 10: Properties of NYE oil 132B
Fluid Property Typical value Units
Pour point <-62 °C
Flash Point 227 °C
Density @ 25 °C Not supplied kg/m3
Viscosity @ 25 °C 28 mm2/s
Manufacturer:
NYE
12 Howland Road
Fairhaven
MA 02719
USA
Distributor:
Corruflex
Pomona
South Africa
Tel: 083 279 8007 - David Kuhn
6.5. KRYTOX FULLY SYNTHETIC OILS
Krytox fully synthetic oils and greases have excellent lubrication properties, which
make them useful in a wide range of critical applications. Krytox is a
perflouropolyether (PFPE) and Storage and Shelf life is claimed to be indefinite if
container as supplied is unopened and stored in clean dry location. The specific
properties are listed in the respective tables,
Manufacturer:
Du Pont Performance Lubricants
Deepwater
NJ 08023
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Distributor:
Chempro
P.O. Box 336
Milnerton
7435
Tel: (021) 550 8181
6.5.1. Krytox 143 AA
Table 11: Properties of Krytox 143 AA
Fluid Property Typical value Units
Pour point -50 °C
Flash Point Not given °C
Density @ 25 °C 1880 kg/m3
Viscosity @ 25 °C 73 mm2/s
6.5.2. Krytox 143 AZ
Table 12: Properties of Krytox 143 AZ
Fluid Property Typical value Units
Pour point -55 °C
Flash Point Not given °C
Density @ 25 °C 1870 kg/m3
Viscosity @ 25 °C 35 mm2/s
6.5.3. Krytox GPL 105
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Table 13: Properties of Krytox GPL 105
Fluid Property Typical value Units
Pour point -36 °C
Flash Point Not given °C
Density @ 25 °C 1900 kg/m3
Viscosity @ 25 °C ±450 mm2/s
6.6. NYE UNIFLOR
This is a Perfloropolyether oil that is chemically inert and will not age, even at high
temperatures.
Manufacturer:
NYE
12 Howland Road
Fairhaven
MA 02719
USA
Distributor:
Corruflex
Pomona
South Africa
Tel: 083 279 8007 - David Kuhn
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6.6.1. NYE Uniflor 8910
Table 14: Properties of NYE Uniflor 8910
Fluid Property Typical value Units
Pour point <-70 °C
Flash Point None °C
Density @ 25 °C 1870 kg/m3
Viscosity @ 25 °C 140 mm2/s
6.6.2. NYE Uniflor 8920
Table 15: Properties of NYE Uniflor 8920
Fluid Property Typical value Units
Pour point <-70 °C
Flash Point None °C
Density @ 25 °C 1880 kg/m3
Viscosity @ 25 °C 240 mm2/s
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7. LUBRICATION TESTS
7.1. TEST EQUIPMENT AND PROCEDURE
A Delay Inertia Mechanism (DIM) is a mechanisms used in SADs as a timing device.
An inertia, or eccentric mass is driven by an acceleration force and retarded by an
oscillating mass through an escapement wheel and gearbox.
A DIM was used for the lubrication tests with a gearbox of which the escapement
mass was increased. The increased mass results in the mechanism moving slower
under the same force. The purpose is to have an amplifying effect of the influence the
lubricants will have at extreme temperatures due to viscosity. The DIM also has an
inertia mass that locks the eccentric wheels in the inactivated state. The inertia mass
did not form part of the set-up and had no influence on the results.
The DIM, shown in Figure 5, was mounted on a base plate together with a small
pneumatic cylinder. An adjustable screw-in type pin on the cylinder ram interfaced
with a pin on one of the eccentric wheels, which locked the DIM in the inactivated
position. This allowed for the centrifuge to stabilize at a predetermined rotating speed
to ensure the acceleration force exerted on the DIM is accurate and constant
throughout the test.
An electrical contact plate was mounted on the base plate to coincide with the pin on
one of the eccentric wheels at the end of its travel to provide an electrical signal at the
end of the wheel’s travel at exactly the same point for every test.
The “Arming” time for of the DIM was taken from the time of the electrical pulse
used to operate the pneumatic cylinder solenoid valve to the point of receiving the
contact plate signal. The pins and contact plate were not adjusted during the test
series in order to make comparisons between the various lubricants. The complete
DIM/angle bracket was mounted in an electrical box to seal the unit off from the
environment. This not only prevented the unit from frosting up during low
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temperature tests, but also prevented temperature loss during set-up and testing. The
sealed electrical box with DIM is shown in Figure 6.
(4)
(3
(2)(1)
Figure 5: The DIM mounted on a base plate (1), with small pneumatic cylinder (2), adjustable screw-in type pin (3) and pin (4) on one of the eccentric wheels
Figure 6: The sealed electrical box with DIM.
The locking pin, used for locking the eccentric wheel of the DIM in the armed
position, was removed in order to allow the DIM to return to the safe or inactivated
position when the acceleration force was removed. This allowed for tests to be
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repeated without opening the box or disturbing the set-up from ambient to low/high
temperature tests.
Initially the complete DIM was ultrasonically cleaned in Methelene Chloride. After a
clean and dry test, the gearbox was removed, lubricated by submerging it in the
lubricant and then spinning the excess lubricant off on a centrifuge at approximately
25G. The gearbox was then fitted to the DIM and the unit sealed in the electrical box.
An acceleration of 20G was used for each test. The ambient temperature test was
followed by the low and high temperature tests, respectively. After these tests, only
the gearbox was removed from the DIM, ultrasonically cleaned and then lubricated
with the next lubricant, using the same procedure.
7.2. TEST RESULTS
Table 16: Relative arming times for ambient tests. No Clean Old
Aeroshell 12 New
Aeroshell 12M20 M100 M1000 Uniflor 8190 NYE Synthetic
oil 132B
1 -1.17 -19.1 -18.68 -16.18 -16.18 -15.76 -18.68 -20.77
2 -0.75 -19.52 -19.1 -16.6 -16.6 -16.6 -19.52 -20.77
3 -0.75 -19.93 -19.52 -17.01 -16.6 -17.01 -20.35 -21.18
4 -0.33 -19.93 -19.93 -17.01 -17.01 -17.01 -20.35 -20.77
5 -0.33 -19.93 -19.52 -17.01 -17.01 -17.43 -20.35 -21.18
6 0.08 -20.35 -19.52 -17.01 -17.01
7 0.5 -20.35 -19.1
8 0.5 -20.35 -19.52
9 0.92 -20.35
10 1.33 -20.35
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Table 17: Relative arming times for cold tests. No Clean Old
Aeroshell 12 New
Aeroshell 12M20 M100 M1000 Uniflor 8190 NYE Synthetic
oil 132B
1 -7.42 35.53 19.27 20.93 23.85
2 Not Not -12.43 -12.43 -15.35 No -9.51 -2.42
3 tested tested -17.43 -15.35 -17.01 arming -14.93 -11.18
4 -19.52 -16.6 -17.85 occurred -17.01 -16.6
5 -19.93 -18.27 -19.1 -19.52
Table 18: Relative arming times for hot tests. No Clean Old
Aeroshell 12 New
Aeroshell 12M20 M100 M1000 Uniflor 8190 NYE Synthetic
oil 132B
1 -19.52 -16.18 -16.18 -16.18 -19.93 -21.18
2 Not Not -19.93 -16.6 -16.6 -16.6 -20.77 -22.44
3 tested tested -19.52 -16.18 -16.6 -17.01 -21.18 -22.02
4 -19.93 -16.18 -16.6 -17.43 -21.18 -22.44
5 -16.18 -17.43 -21.18 -22.44
-30
-20
-10
0
10
20
30
40
0 2 4 6 8 10 12
Measurement number
Perc
anta
ge (%
)
Clean Old Aeroshell 12 New Aeroshell 12M20 M100 M1000Uniflor 8190 NYE Synthetic oil 132B
Figure 7: Relative arming times for ambient tests
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-30
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6
Measurement number
Perc
anta
ge (%
)
Clean Old Aeroshell 12 New Aeroshell 12M20 M100 M1000Uniflor 8190 NYE Synthetic oil 132B
Figure 8: Relative arming times for cold tests
-30
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6
Measurement number
Perc
anta
ge (%
)
Clean Old Aeroshell 12 New Aeroshell 12M20 M100 M1000Uniflor 8190 NYE Synthetic oil 132B
Figure 9: Relative arming times for hot tests
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Table 19: DIM temperature as function of time delay during cold test
Measurement No.
Time delay (s)
DIM temperature (oC)
1 35 -50
2 70 -49
3 105 -47
4 140 -45
5 175 -43
6 210 -41
7 245 -40