Laboratory Test Report
Report No.:
Date Issued:
This report may not be reproduced except in full.
It contains no corrections or erasures.
08CA65949-01
22 January 2009
SUBJECT:
Iridium 9505/A Mount
REQUESTED BY:
Flightcell International Ltd
98 Vickerman Street
PO Box 1481
Nelson
New Zealand
INSTRUCTIONS:
Vibration testing based on Method 514.5 – Vibration of Mil-Std-810F
“Department of Defence Test Method Standard for Environmental
Engineering Considerations and Laboratory Tests”. Shock testing to
customer’s specification.
CONTENTS:
General
Date of test
Description
Results A: Mil-Std 810F – Method 514.5 Vibration
Results B: Shock Testing
Appendix A: Representative Vibration Test Results
Appendix B: Representative Shock Test Results
SUMMARY:
Test results in this report confirm that the Iridium 9505/A Mount was tested
according to Method 514.5 – Vibration of Mil-Std-810F and according to
the customer’s shock test specification. The ball-joint slipped under shock
loading but no damage was observed on the mount or the 9505 telephone.
APPROVED BY:
TESTED BY:
R.A. Hills
Technical Manager
Christopher Bennetts
Senior Project Engineer
10 VANADIUM PLACE, PO BOX 9194, ADDINGTON 8243, CHRISTCHURCH, NEW ZEALAND
TEL: +64 3 940 4400 FAX: +64 3 940 4411 EMAIL: enquiries@nz.ul.com INTERNET: www.nz.ul.com
Page 1 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
GENERAL
a)
As detailed in this report, one specimen of the Iridium 9505/A Mount was received for
testing.
b)
The results detailed in this report relate only to the specimen submitted by the
customer.
c)
The Iridium 9505/A Mount was tested based on Method 514.5 – Vibration of Mil-Std810F and according to a customer-specified shock test.
d)
All testing was carried out under the following environmental conditions, unless
otherwise noted:
Ambient temperature
Relative humidity
Atmospheric pressure
15°C to 25°C
30 % to 60 %
86 kPa to 106 kPa
e)
Note: N/R = Not Relevant to design assessed, N/T = Not Tested at manufacturer’s
request, EUT = Equipment Under Test, DNC = Did Not Comply.
f)
The reported expanded uncertainties (U ) listed below are based on standard
uncertainties multiplied by a coverage factor k = 2, and define an interval ±U
providing a level of confidence of approximately 95%.
i.
acceleration
0.05 m/s2 – 500 m/s2
±5%
DATE OF TEST
Testing was completed on 17 December 2008.
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 2 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
DESCRIPTION
The Iridium 9505/A Mount was a lightweight anodized aluminium cradle for a satellite
telephone. It was designed to hold a 9505 or 9505A phone in a vehicle environment at an
angle determined by the adjustable base. The two ball-joints on the base were tightened via a
single handle. For the purpose of this test a telephone was placed in the cradle and the circular
base was clamped rigidly to the shock-test surface.
Approximate dimensions [mm]:
Cradle: L 220 x W 70 x H 70
Ball-joint base: H 90 x Diameter 60
Iridium 9505/A Mount: Overall View Showing Adjustable Base
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 3 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Iridium 9505/A Mount: Overall View Showing Placement of 9505 Satellite Telephone
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 4 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
RESULTS A: Method 514.5 – Vibration from Mil-Std-810F “Department
of Defence Test Method Standard for Environmental Engineering
Considerations and Laboratory Tests”.
CLAUSE 1 SCOPE
Applied
CLAUSE 2 TAILORING GUIDANCE
Noted
CLAUSE 3 INFORMATION REQUIRED
Noted
Clause 3.1 Pre-test
Noted
(1) Test fixture requirements: The base of the Iridium 9505/A Mount was
clamped to the vibration generator using bolts and washers.
(2) Test fixture modal survey was not performed for this test.
(3) Test item / fixture modal survey was not performed for this test.
(4) Vibration exciter control strategy: Single point control.
(5) Test tolerances: ±3 dB over the frequency range. Out of tolerance
bandwidths <5 % of total test control bandwidth.
(6) Combined Environments were not required for this test.
(7) Test schedule and duration of exposure: Procedure I – General
Vibration. Category 14. Duration = 1 hour per axis
(8) Axes of exposure: The samples were exposed to vibration in each of
the three axes defined in the following photograph. Measurement
instrumentation configuration: Current feedback of piezoelectric
acceleration signals via LDS controller and associated software.
(9) Test shutdown procedures: Test shuts down if control signal
acceleration departs from the desired profile by ± 6 dB.
(10) Test interruption recovery procedure: Test stopped in the event of a
test item failure.
(11) Test completion procedure: Test is complete when all elements of the
test item have successfully passed a complete test.
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 5 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Z-AXIS
X-AXIS
Y-AXIS
Iridium 9505/A Mount Set Up For X-Axis Vibration And Showing
Other Axis Definitions For The Purposes Of This Testing
Clause 3.2 During Test
Noted
An Iridium 9505 satellite phone was installed in the Mount to determine
whether the vibration would cause loosening.
Clause 3.3 Post-test
Noted
Visual checks of the Mount and phone were conducted following testing.
CLAUSE 4 TEST PROCESS
Applied
Clause 4.1 Test Facility
Applied
Clause 4.1.1 Procedure I – General Vibration
Applied
Vibration testing was conducted using Underwriters Laboratories’
electrodynamic shaker.
Clause 4.1.2 Procedure II – Loose Cargo Transportation
This report may not be reproduced except in full.
It contains no corrections or erasures.
N/R
Page 6 of 19
Report No.:
Date Issued:
Clause 4.1.3 Procedure III – Large Assembly Transportation
08CA65949-01
22 January 2009
N/R
Clause 4.1.4 Procedure IV – Assembled Aircraft Store Captive Carriage
and Free Flight
N/R
Clause 4.2 Controls
Applied
Clause 4.2.1 Control Strategy
Applied
Clause 4.2.1.1 Acceleration input control strategy
Applied
Clause 4.2.1.2 Force control strategy
N/R
Clause 4.2.1.3 Acceleration limit strategy
N/R
Clause 4.2.1.4 Acceleration response control strategy
N/R
Clause 4.2.1.5 Open loop waveform control strategy
N/R
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 7 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Clause 4.2.2 Tolerances
Applied
The following tolerances were applied:
Clause 4.2.2.1 Acceleration Spectral Density:
Applied
a. Vibration environment: Acceleration spectral density was within
±3 dB over the specified frequency range
b. Vibration measurement: The system provided acceleration spectral
density measurements within ±0.5 dB of the vibration level of the
transducer mounting surface over the required frequency range. The
control system utilised 4096 frequency lines, with 250 degrees of
freedom.
Clause 4.2.2.2 Peak Sinusoidal Acceleration
Noted
Clause 4.2.2.3 Frequency Measurement
Applied
The vibration measurement system provided frequency measurements
within ±1.25 % at the transducer mounting surface over the required
frequency range.
Clause 4.2.2.4 Cross axis accelerations
Noted
Clause 4.3 Test Interruption
N/R
Clause 4.4 Test Setup
Applied
Mounting method as per Clause 3.1. Gravitational orientation with respect
to gravity was maintained as shown in the photograph on page 6.
Clause 4.5 Test Execution
Clause 4.5.1 Preparation for test
Applied
Applied
A visual examination was carried out before the commencement of the test
and no existing damage was observed.
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 8 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Clause 4.5.2 Procedure I – General vibration
Applied
Category 14: “Rotary wing aircraft – Helicopter” was chosen as helicopter
transportation was thought to be the worst in-service condition for this
item.
No specific helicopter model was provided, so an average value was
chosen using the blade frequencies in Table 514.5C-IV of Mil-Std 810F.
Four blades and a frequency of 4.35 Hz were selected. “General” location
within the vehicle.
Four blade-passing harmonics were superimposed upon a random
vibration spectrum between 10 Hz and 500 Hz as shown below:
Random Vibration
Frequency [Hz]
Acceleration [g2/Hz]
10
0.001
100
0.01
300
0.01
500
0.001
Sinusoidal Tone
Frequency [Hz]
Amplitude [gn]
1
4.35
0.11
2
17.4
1.74
3
34.8
2.5
4
52.2
1.5
Further test details and a representative graphical output are included in
Appendix A.
Clause 4.5.3 Procedure II – Loose cargo transportation
N/R
Clause 4.5.4 Procedure III – Large assembly transportation
N/R
Clause 4.5.5 Procedure IV – Assembled Aircraft Store Captive Carriage
and Free Flight
N/R
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 9 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
CLAUSE 5 ANALYSIS OF RESULTS
Complied
The sample was subjected to visual checks following testing. No physical
damage was observed. The satellite phone was held satisfactorily in the
Iridium 9505/A Mount and the base joint angles were maintained.
CLAUSE 6 REFERENCE/RELATED DOCUMENTS
Noted
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 10 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
RESULTS B: Shock Testing
This testing was performed to the customer specification, which was not
known to relate directly to any published standard.
The Iridium 9505/A Mount was subjected to the following test parameters:
SHOCK PULSE PARAMETERS
Peak acceleration [g]
20
Effective pulse length [ms]
25
Pulse shape
half sine
Tolerances on pulse shape
according to ISO
Shocks pulses in each axis
3 positive, 3 negative
Total number of shocks
18
Refer to Appendix B for further test details and representative software
outputs.
An Iridium 9505 phone was installed in the Mount to determine whether
the shocks would result in loosening.
Gravitational orientation of the EUT was maintained as per the operational
setup (see photograph on page 6).
The base of the Iridium 9505/A Mount was clamped to the vibration
generator using bolts and washers.
TEST PROCESS
Instrumentation
Shock test control was by means of a single piezoelectric accelerometer
(PCB type 353B03).
Visual and Functional Checks
Visual checks were carried out on the Iridium 9505/A Mount before and
after testing. The ball-joint fastener was screwed in as tight as was
practical with one hand.
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 11 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
RESULTS
During the repeated shocks the angle of the ball joints changed (<30°). In
some cases this slippage resulted in the cradle contacting the mounting
surface during subsequent shocks. The sample and satellite phone were
subjected to a visual check following testing and no detrimental effects
were observed.
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 12 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
APPENDIX A: Representative Vibration Test Results
Project File Name:
Profile Name:
Test Type:
Run Folder:
General Helicopter Mil-Std Cat14.prj
Iridium Mount vertical axis
Sine on Random
.\RunDefault Oct 31,2008 14-39-09
(gn)²/Hz
67.5274
profile(f)
high-abort(f)
10.0000
low-abort(f)
high-alarm(f)
1.0000
low-alarm(f)
control(f)
0.1000
0.0100
0.0010
0.0001
2.56
10.00
100.00
552.96
Frequency (Hz)
Level: 100 %
Control RMS: 2.975885 gn
Lines: 1600
Frame Time: 3.200000 Seconds
Remaining Time: 00:00:00 DOF: 250
Full Level Elapsed Time: 01:00:00
Demand RMS: 2.996112 gn
dF: 0.312500 Hz
Data saved at 02:51:34 PM, Friday, October 31, 2008
Report created at 02:51:36 P.M., Friday, October 31, 2008
Shaker Parameters
Shaker Name:
Positive Displacement Limit Peak:
Negative Displacement Limit Peak:
Maximum Velocity Peak:
Maximum Acceleration Peak:
Minimum Drive Frequency:
Maximum Drive Frequency:
Maximum Drive Peak:
Orientation:
Assume Noisy Measurement?:
This report may not be reproduced except in full.
It contains no corrections or erasures.
LDS - V830-335
1.00 in
1.00 in
78.70 in/s
180.00 gn
5.00 Hz
3000.00 Hz
10.00 Volts
Vertical
Yes
Page 13 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Channel Parameters
Input Channel Parameter
Input
3
Type
Control
Max. Volts
1.00
mv/(gn)
10.05
Weighting
1.00
Coupling
AC
Output Channel Parameter
Output
1
Type
Output
Max. Volts
10.00
Control Parameters
Test Parameters
Number of Spectral Lines:
Max. Test Frequency:
Measurement Strategy:
Line Abort Ratio:
Line Abort Number:
Averaging Number:
Drive Limit:
Sigma Clip:
Data Points/Frame:
Frame Time:
Sampling Rate:
DOF:
dT:
dF:
1600
500.00 Hz
Single Channel
0.30
480
125
10.00 Volts
Disable
4096
3.200000 Seconds
1280 Hz
250
0.000781 Seconds
0.312500 Hz
Pre-test parameters
Method of Acquiring the Loop Frequency
Response Function:
Initial Peak Drive:
Ramp-Up Rate:
Response Level Goal:
Maximum Peak Drive:
Measure During Pre-Test
0.005000 Volts
Fast
10.00 %
1.000000 Volts
Profile Parameters
Profile name:
profile 1
Iridium Mount vertical axis
Broadband Acceleration RMS:
Broadband Velocity RMS:
Broadband Displacement RMS:
1.790427 gn
1.068702 in/s
0.006902 in
Narrowband Acceleration RMS:
Narrowband Velocity RMS:
Narrowband Displacement RMS:
2.402051 gn
5.602560 in/s
0.058428 in
Overall Acceleration RMS:
2.995910 gn
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 14 of 19
Report No.:
Date Issued:
Overall Velocity RMS:
Overall Displacement RMS:
5.703578 in/s
0.058834 in
Overall Expected Acceleration (Peak):
Overall Expected Velocity (Peak):
Overall Expected Displacement (Peak):
8.987731 gn
17.110733 in/s
0.353007 in
Shaker Acceleration (Peak):
Shaker Velocity (Peak):
Shaker Displacement (Peak-Peak):
180.0000 gn
78.7000 in/s
2.0000 in
RMS Limits come from:
High Abort:
High Alarm:
Profile:
Low Alarm:
Low Abort:
Calculated based on table
3.572382 gn (99.53 %)
2.529044 gn (41.25 %)
1.790427 gn
1.267527 gn (-29.21 %)
0.897341 gn (-49.88 %)
08CA65949-01
22 January 2009
Profile Table:
Frequency
Hz
10.0
100.0
300.0
500.0
Left Slope
dB/Oct
3.01043
Const. Acce.
-13.5692
Acceleration
(gn) Peak
0.001
0.01
0.01
0.001
Velocity
(in/s) Peak
0.00614479
0.00614479
0.00204826
0.000122896
Displacement
(in) Peak
0.000195595
1.95595e-005
2.17328e-006
7.82379e-008
Right Slope
dB/Oct
3.01043
Const. Acce.
-13.5692
Sine Tone Profile Parameters
Sweep in harmonic mode:
No
Amplitude Peak:
Amplitude High Alarm:
Amplitude High Abort:
Ramping Up/Down rate:
Sweep Low Frequency:
Sweep Start Frequency:
Sweep High Frequency:
Sweep Mode:
Sweep Rate:
Initial Sweep Direction:
Enable burst this tone on and off rapidly:
Tone Number 1
0.11 gn
3 dB
6 dB
12 dB/sec
4.35 Hz
4.35 Hz
4.35 Hz
Linear
0 Hz/Sec
Up
No
Amplitude Peak:
Amplitude High Alarm:
Amplitude High Abort:
Ramping Up/Down rate:
Sweep Low Frequency:
Sweep Start Frequency:
Sweep High Frequency:
Sweep Mode:
Sweep Rate:
Initial Sweep Direction:
Enable burst this tone on and off rapidly:
Tone Number 2
1.74 gn
3 dB
6 dB
12 dB/sec
17.4 Hz
17.4 Hz
17.4 Hz
Linear
0 Hz/Sec
Up
No
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 15 of 19
Report No.:
Date Issued:
Amplitude Peak:
Amplitude High Alarm:
Amplitude High Abort:
Ramping Up/Down rate:
Sweep Low Frequency:
Sweep Start Frequency:
Sweep High Frequency:
Sweep Mode:
Sweep Rate:
Initial Sweep Direction:
Enable burst this tone on and off rapidly:
Tone Number 3
2.5 gn
3 dB
6 dB
12 dB/sec
34.8 Hz
34.8 Hz
34.8 Hz
Linear
0 Hz/Sec
Up
No
Amplitude Peak:
Amplitude High Alarm:
Amplitude High Abort:
Ramping Up/Down rate:
Sweep Low Frequency:
Sweep Start Frequency:
Sweep High Frequency:
Sweep Mode:
Sweep Rate:
Initial Sweep Direction:
Enable burst this tone on and off rapidly:
Tone Number 4
1.5 gn
3 dB
6 dB
12 dB/sec
52.2 Hz
52.2 Hz
52.2 Hz
Linear
0 Hz/Sec
Up
No
08CA65949-01
22 January 2009
Schedule Parameters
schedule 1
schedule name: Schedule1
0:0:10 at Level 50.0 %
SoR On 1,2,3,4, Off 5,6,7,8,9,10,11,12, Broadband On
0:0:10 at Level 50.0 %
1:00:0 at Level 100.0 %
Save All Panes
Auto-Save Signals
Pre-Test Result
Drive
input 3
Noise
0.000000 volts
0.018348 volts
At Level 10 %
0.013413 volts
0.012127 volts
This report may not be reproduced except in full.
It contains no corrections or erasures.
Estimated at Full Level
0.134128 volts
0.121272 volts
Page 16 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
APPENDIX B: Representative Shock Test Results
Project File Name:
Profile Name:
Test Type:
Run Folder:
iDesign 20g max.prj
Iridium Mount y-axis 20gn 25mSec
Classical Shock
.\RunDefault Dec 17,2008 13-57-04
gn
27.5000
24.0000
profile(t)
21.0000
high-abort(t)
18.0000
low-abort(t)
15.0000
control(t)
12.0000
9.0000
6.0000
3.0000
0
-3.0000
-6.0000
-9.0000
-12.0000
-15.0000
-18.0000
-21.0000
-24.0000
-27.0000
-30.0000
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
0.04
0.05 0.05
Time (Seconds)
Level: 100 %
Frame Time: 0.170667 Seconds
Full Level Elapsed Pulses: 6
Demand RMS: 7.253651 gn
Amplitude: 20.000000 gn
Block Size: 512
Control Peak: 20.461372 gn
dT: 0.000333 Seconds
Remaining Pulses: 0
Elapsed Pulses: 14
Control RMS: 7.429550 gn
Demand Peak: 20.000000 gn
Pulse Type: Half Sine
Data saved at 01:59:10 PM, Wednesday, December 17, 2008
Report created at 01:59:26 P.M., Wednesday, December 17, 2008
Shaker Parameters
Shaker Name:
Positive Displacement Limit Peak:
Negative Displacement Limit Peak:
Maximum Velocity Peak:
Maximum Acceleration Peak:
Minimum Drive Frequency:
Maximum Drive Frequency:
Maximum Drive Peak:
Orientation:
Assume Noisy Measurement?:
This report may not be reproduced except in full.
It contains no corrections or erasures.
LDS - V830-335
0.08 ft
0.08 ft
1998.98 mm/s
75.00 gn
5.00 Hz
3000.00 Hz
10.00 Volts
Vertical
No
Page 17 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Channel Parameters
Input Channel Parameter
Input
3
Type
Control
Max. Volts
1.00
mv/(gn)
10.53
Weighting
1.00
Coupling
AC
Output Channel Parameter
Output
1
Type
Output
Max. Volts
10.00
Control Parameters
Test Parameters
Block Size:
Averaging Number:
Drive Limit:
Pulse Interval:
Point Abort Ratio:
Low-Pass Filter Type:
Data Points/Frame:
Frame Time:
Sampling Rate:
dT:
Maximum Analysis Frequency:
SRS Analysis:
Auto
4
10.00 Volts
3.000 seconds
0.10
Do not apply filter
512
0.170667 Seconds
3000 Hz
0.000333333 Seconds
1318.36 Hz
Disable
Pre-test parameters
Method of Acquiring the Loop Frequency
Response Function:
Initial Peak Drive:
Ramp-Up Rate:
Response Level Goal:
Maximum Peak Drive:
Measure during close-loop pre-test
0.001000 Volts
Fast
10.00 %
1.000000 Volts
Profile Parameters
Profile name:
Pulse Type:
Amplitude:
Pulse Width:
Main Pulse Tails:
Compensation Template:
Pre-Pulse Height:
Post Pulse Height:
Abort Setting:
This report may not be reproduced except in full.
It contains no corrections or erasures.
profile 1
Iridium Mount y-axis 20gn 25mSec
half sine
20.00 gn
25.00 ms
ISO Standard
Pre-Post half sine
80.00 %
80.00 %
ISO Standard
Page 18 of 19
Report No.:
Date Issued:
08CA65949-01
22 January 2009
Schedule Parameters
schedule 1
schedule name: Schedule1
1 Pulses at Level 50.00 %
3 Pulses at Level 100.00 %
Inverse Pulse
3 Pulses at Level 100.00 %
Save All Panes
Auto-Save Signals
Pre-Test Result
Drive
input 3
Noise
0.000000 volts
0.000276 volts
At Level 10 %
0.108850 volts
0.019852 volts
Estimated at Full Level
1.088501 volts
0.198517 volts
Run log
Dactron Dual DSP Shaker Control System
Classical Shock Test Run Log
ENTRY TIME
/ELAPSED
00:00:00/ 0
00:00:02/ 1
00:00:04/ 2
00:00:07/ 3
00:00:11/ 4
00:00:14/ 5
00:00:16/ 6
00:00:20/ 7
00:00:22/ 7
00:00:22/ 8
00:00:26/ 9
00:00:28/ 10
00:00:31/ 11
00:00:35/ 12
00:00:37/ 13
00:00:40/ 14
00:00:45/ 14
00:00:45
00:00:45/ 14
00:00:45/ 14
00:00:45/ 14
LEVEL
0.00 %
Open
0.53 %
2.12 %
8.46 %
10.00 %
10.00 %
10.00 %
10.00 %
50.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
100.00 %
13:57:05, Wednesday, December 17, 2008
CTL/DEMAND
(Peak)
0.036/ 2.000 gn
0.106/ 2.000 gn
0.378/ 2.000 gn
1.664/ 2.000 gn
1.980/ 2.000 gn
1.999/ 2.000 gn
1.962/ 2.000 gn
9.977/10.000 gn
19.076/20.000 gn
19.403/20.000 gn
19.519/20.000 gn
20.737/20.000 gn
20.540/20.000 gn
20.461/20.000 gn
Controller
20.461/20.000 gn
SOURCE
DESCRIPTION
User Command
Controller
Controller
Controller
Controller
Controller
Controller
Controller
User Command
Controller
Controller
Controller
Controller
Controller
Controller
Controller
Controller
'control(t),' Saved Signals
Controller
Start the Test
Running in pre-test
System paused after pre-test
Run Scheduled Test
Running in scheduled test
All Panes saved to the disk.
End of Test
Full level elapsed 6
Total elapsed 14
END OF REPORT
This report may not be reproduced except in full.
It contains no corrections or erasures.
Page 19 of 19