ASTM 1597 Status of P

1
ASTM 1597Status of PB

• Presented by W. A. Driscoll
• February 8th, 2006
• F01.018 Subcommittee Meeting
• Phoenix, Arizona

2
Topics

• Inter Laboratory Study (ILS) Background
• History of Changes Made During PB
• 2nd Round Of Tests
• Who, What Why
• Observations Comments From Some Labs
• Data
• Recommendations and Discussions

3
ILS Steps

• Ruggedness Test
• Pilot Test
• Full PB

4
Ruggedness test

• A cost-effective screening procedure performed by
  one laboratory that produces a repeatability
  statement.
• This helps pinpoint variables associated with the
  performance of a test method, allowing the
  committee to determine how control of such
  variables should be specified within the method

5
Pilot Test

• Generally utilized to confirm uniform
  interpretation of method modifications
• Several labs analyze one material and results are
  compared
• Outlier labs may have a different understanding
  of method requirements
• Instructions can be modified as required prior to
  full ILS

6
Full PB

• Suggest 8-12 labs
• Minimum 6 labs used
• Each test performed (average of 5 repeated
  depressions) at least twice
• On at least 4 different parts
• We add 3 different types of switches
• Have added multiple probes in the PB
• 500 depressions at each lab (gtthousands of
  parameters recorded)

7
1st Set Of Tests Presented January 2005

• 6 Labs (5 Companies with one site running two
  different pieces of equipment)
• One average of 5 repeated tests on the specified
  key on each of the switches (5-6 switches of each
  tactile, metal domed and poly domed)
• Ken Klein brought to our attention need for
  another replicate which was subsequently
  confirmed through ASTM

8
2nd Round Tests

• Two sets of complete tests (average of 5
  measurements on the designated keypad of each
  switch) needed January 2005
• Test refined to include a metal probe on
  non-tactile switches January 2005
• Test refined to include more than just the
  contact and actuation force. A total of 12
  parameters to be measured if possible June 2005
• Test refined to include a rounded tip metal probe
  provided by Denny N for using on non-tactile
  switches June 2005

9
6 Actuation Contact Measurements

• Actuation Force (Fmax - maximum force during
  travel)
• Actuation Travel (Tfmax - displacement at maximum
  force)
• Minimum Force (Fmin - minimum after actuation)
• Minimum Travel (Tfmin - displacement at minimum
  after actuation)
• Contact Force (Fc - force when specified
  resistance is achieved)
• Contact Travel (Tc - displacement when specified
  resistance is achieved)

10
6 Break And Return Measurements

• Break Force (Fb Force when specified resistance
  is exceeded)
• Break Travel (Tb - displacement when specified
  resistance is exceeded)
• Minimum Force (Frmin - minimum during return)
• Minimum travel (Tfrmin - displacement at minimum
  during return)
• Maximum Force (Frmax - maximum during return)
• Maximum Travel (Tfrmax - displacement at minimum
  during return)

11
Participating Labs - 2nd Round

• Completed
• Tekra Mike Suchocki
• Some missing data points
• Valmark Brando Balarezo
• Only one set of tests supplied
• Advanced Technologies Denny Nelen / Ken Gann
• Testing complete - data not received yet
• Partial data 2 tests
• Snaptron Walter Goodrich (2 sets completed
  before expansion to 12 parameters)
• Not started on 2nd test
• GM Nameplate Dennis Webster (2 different pieces
  of equipment)
• Nelson Nameplate John Kunsch

12
Probes Now Used In 2nd Set of Tests

• Non tactile switch
• Valmark
• Flat tip metal
• Round tip metal
• Hemispherical aluminum
• Elastomeric
• Rubber
• Tekra
• 1 Dia aluminum
• Red rubber
• White rubber

13
Probes Now Used In 2nd Set of Tests

• Metal Dome
• Valmark
• Round trip metal
• Flat tip metal (Brass)
• Hemispherical Aluminum
• Tekra
• Brass

14
Probes Now Used In 2nd Set of Tests

• Poly Dome
• Valmark
• Flat tip metal (Brass)
• Round tip metal
• Hemispherical aluminum
• Tekra
• 1 Aluminum hemisphere

15
Lab Capability

• Valmark
• Forces Only (No Travel)
• Actuation Contact
• Actuation, minimum, contact
• Break and Return
• Break, minimum, maximum
• Tekra
• All 12 parameters with reservations on travel
• Advanced Technologies
• All 12 parameters with no reservations although
  return data has to be extracted from ASCII file -
  automated equipment

16
Valmark Comments

• I found that the non-tactile switch is more
  difficult to collect the data because the Fmax
  and Fb are not as stable as of the tactile
  switches (metal dome in particular)
• With non tactile switches I often had to take
  more readings until I could get 5 readings with
  least fluctuation. I also noticed that when I
  stop moving the probe during the actuation
  period, the force dropped slightly. This may be
  due to the overlay itself temporarily losing its
  holding property (maybe there is a Physics term
  for this) in molecular level.

17
Tekra Comments

• Because my setup is manual, and I start from 0
  force the travels can vary considerably between
  specimens. This is because the first 10 or so
  microns of travel are spent closing the air gap.
• Because the switch is not solidly mounted there
  can be from 0.1 to 0.2 oz. of force absorbed just
  flattening the switch and taking out the
  bagginess between the layers.
• Because of the above, any determination of the
  force/actuation slope should exclude that early
  part of the curve before the slope becomes
  consistent. See included curves.
• There seem to be a trend of decreasing force
  values as the readings progress 1st reading
  highest, 2nd reading lower, 3rd reading lower
  than 2nd, etc. Could be that layers are heating
  up causing more flexibility (lower modulus). Or,
  bottoming out the flat metal probe during contact
  closure (0.01mm over-travel) could be weakening
  the switch note lower force readings across the
  board on test 2
• Time consuming test

18
Non-Tactile Aluminum Round TipContact Force
19
Non-Tactile Red ElastomericContact Force
20
Non-Tactile White ElastomericContact Force
21
Non-Tactile Round TipContact Force
22
Non-Tactile Brass Flat TipContact Force
23
Metal Dome - Round Tip MetalActuation Force
24
Metal Dome - Round Tip MetalContact Force
25
Metal Dome Aluminum HemisphereActuation Force
26
Metal Dome Aluminum HemisphereContact Force
27
Metal Dome Flat Tip BrassActuation Force
28
Metal Dome Flat Tip BrassContact Force
29
Poly Dome - Round Tip MetalActuation Force
30
Poly Dome - Round Tip MetalContact Force
31
Poly Dome Aluminum HemisphereActuation Force
32
Poly Dome Aluminum HemisphereContact Force
33
Poly Dome Flat Tip BrassActuation Force
34
Poly Dome Flat Tip BrassContact Force
35
Recommendations (Questions) to Committee

• Should we look at a different set of non-tactile
  and/or poly dome switches?
• Cut down the number of switches
• 6 non tactile
• 6 domed
• 3 poly
• 3 metal
• Ruggedness Study
• We use one laboratory to study the various test
  conditions (probes, parameters, etc.) impact on
  the results
• Which Lab

36
Recommendations (Questions) to Committee

• Pilot Test
• Which Labs? Will the same ones be willing to do
  it again?
• Once we feel we have refined the test
  sufficiently (especially for non-tactile
  switches), we do 1-3 switches at each lab to
  determine
• Generally utilized to confirm uniform
  interpretation of method modifications
• Several labs analyze one material and results are
  compared
• Outlier labs may have a different understanding
  of method requirements
• Instructions can be modified as required prior to
  full ILS
• We use the ASTM resources to coordinate
• Technical contact on committee
• Statistical contact on committee