Eric Katzen worked as an intern at NASA's Hazardous Gas Detection Laboratory (HGDL) under the mentorship of electrical engineer Reggie Martin. Some of his responsibilities included developing leak test equipment, procedures, and calibrating helium mass spectrometers. Specifically, he developed a Leak Tester Cart to test for leak rates, amended HGDL procedures to conform with industry standards, calibrated helium mass spectrometers, tested fittings for maximum leak rates, and created a webpage organizing leak detection specifications and standards. Through his work, he gained valuable experience in leak detection techniques and helping improve HGDL testing operations.

1. NASA-KSC Intern Abstract
07/18/16
Hazardous Gas Detection Laboratory (HGDL)
Student Name: Eric Katzen
Academic Level: Senior
Academic Major: Mechanical Engineering
Academic Institution: Hofstra University
Mentor Name: Reggie Martin
Job Title: Electrical Engineer
Directorate: NASA Engineering (NE)
Division: Electrical
Branch: Ground Controls

2. Abstract
1. Introduction
I work under the NE-EG branch in the Hazardous Gas Detection Laboratory (HGDL) performing
duties such as developing leak test equipment, developing procedures, calibration of helium mass
spectrometers, performing fitting leak tests, and gathering other miscellaneous test data. I also
developed a webpage that organized various standards and specifications.
2. HGDL Overview
The HGDL performs many functions such as design and development of prototypes, fabrication
of test equipment, and functional system testing. Examples of HGDL applications include
combustible gas detection, purge processing, process monitoring, and gas analysis.
3.Work Efforts and Results
3.1. Leak TesterCart
I’m developing, building, and testing a Leak Tester Cart comprising of two test ports and an
electromagnetic valve test port with two roughing pumps for varying head. I incorporated two
pressure transducers, one that reads 10 torr and another at 1000 torr. I needed to provide a large
pressure range to ensure internal pressure is at a vacuum and the gas samples can be read above
and below atmospheric pressures. Each pressure transducer has a performance accuracy
depending on the range at which it is reading as seen in Figure 1. To test the internal leak rate
and obtain consistent results, I performed a leak test on various fittings and components as I was
building to have approximately a 10 mtorr/min leak rate throughout the system. Once I pumped
down my system to a certain pressure, I turned the pump off and measured the leak rate every
minute for ten minutes. I provided 3 sets of measurements to eventually indicate an average leak
rate. At first, I had trouble obtaining a proper leak rate and vacuum pressure; I had to change the
fittings, valves, and hoses many times, a pressure transducer twice, and the pump once before
obtaining adequate data. Using the torque wrench technique, my data still showed signs of
leakage. Eventually after using a normal wrench to tighten the fittings, I was able to acquire an
optimized leak rate and vacuum pressure. Since my initial design is for proof of concept, a torque

3. wrench was not required. My opinion is that a normal wrench had an improved effect on
minimizing the leak rate between components and fittings because I needed more torque then
what was indicated on Table 11 Installation Torque from KSC-SPEC-Z-00080.
Figure 1
3.2. Procedural Amendments
I amended the HGDL procedures to conform with ASTM Helium Leak Test Procedures for
multiple operations which include: Positive Pressure Leak Decay Test, Vacuum Decay Leak
Test, Leak Identification (Visual Inspection, Blank-Off and Retest, helium bag, last resort, and
high and low flow rate), Helium Leak Location Testing, and Helium leak Test – Out/In with
Bag. During the amendment process, I matched the ASTM standards with the HGDL procedures
as a reference.
3.3. Calibration
I provided a spreadsheet of test results for three leak calibrators to Measure Leak Rate vs.
Present Leak Rate (Figure 3) and Present Leak Rate vs. Relative Error (Figure 4) of the helium
mass spectrometer. I calculated the exponential decay rate of the Labeled Leak Rate for each
leak calibrator to determine its Present Leak Rate and matched it with the readings on the helium
mass spectrometer as seen in Figure 2. The reason for calculating the exponential decay of the
Labeled Leak Rate was that the calibrators themselves leak over time even when not using the
mass spectrometer. The Measured Leak Rate is the number indicated by the mass spectrometer.
0.01 torr ± 1.96% rdg
0.05 torr ± .93% rdg
0.1 torr ± .52% rdg
0.5 torr ± .24% rdg
0.75 torr ± .23% rdg
1 torr ± .24% rdg
2.5 torr ± 21% rdg
5 torr ± .11% rdg
7.5 torr ± .08% rdg
10 torr ± .07% rdg
Accuracy

4. The Relative Error represent how accurate the mass spectrometer is. It shows how much the
SCCS (Standards cc/sec) deviates from what the leak rate should be. These values were obtained
from the equation of the line to formally calibrate the mass spectrometer.
Figure 2
Figure 3 Figure 4
y = 8E-10x + 4E-09
0.00E+00
5.00E-08
1.00E-07
1.50E-07
2.00E-07
2.50E-07
3.00E-07
3.50E-07
0 100 200 300 400 500
PresentLeakRate(standardscc/sec)
Measured Leak Rate (AU)
MeasureLeak Rate vs. Present
Leak Rate
-60.00
-40.00
-20.00
0.00
20.00
40.00
60.00
80.00
100.00
0.00E+00 1.00E-07 2.00E-07 3.00E-07
Relativeerror(%)
Present Leak Rate (standards cc/sec)
PresentLeak Rate vs. Relative
Error
S/N FC10671
CAL.DATE 9/18/2015
LIFE (PER YEAR) 10%
YEARS 1
LABELED LEAK RATE 1.10E-07
PRESENT/TRUE LEAK RATE 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08 9.90E-08
MEASURE LEAK RATE ITERATIONS 93 89 88 85 92 94 95 97 98 97
SCCS 6.94E-08 6.62E-08 6.54E-08 6.30E-08 6.86E-08 7.02E-08 7.10E-08 7.26E-08 7.34E-08 7.26E-08
RELATIVE ERROR -29.90 -33.13 -33.94 -36.36 -30.71 -29.09 -28.28 -26.67 -25.86 -26.67
S/N 4595
CAL.DATE 1/25/2007
LIFE (PER YEAR) 10%
YEARS 9
LABELED LEAK RATE 4.68E-08
PRESENT/TRUE LEAK RATE 1.81313E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08 1.81E-08
MEASURE LEAK RATE ITERATIONS 40 44 45 45 44 44 45 48 50 49
SCCS 2.70E-08 3.02E-08 3.10E-08 3.10E-08 3.02E-08 3.02E-08 3.10E-08 3.34E-08 3.50E-08 3.42E-08
RELATIVE ERROR 48.91 66.56 70.98 70.98 66.56 66.56 70.98 84.21 93.04 88.62
S/N 4315
CAL.DATE 8/28/2010
LIFE (PER YEAR) 0.30%
YEARS 6
LABELED LEAK RATE 2.90E-07
PRESENT/ TRUE LEAK RATE 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07 2.85E-07
MEASURE LEAK RATE ITERATIONS 350 360 380 390 370 370 370 370 370 370
SCCS 2.75E-07 2.83E-07 2.99E-07 3.07E-07 2.91E-07 2.91E-07 2.91E-07 2.91E-07 2.91E-07 2.91E-07
RELATIVE ERROR -3.45 -0.64 4.98 7.79 2.17 2.17 2.17 2.17 2.17 2.17

5. 3.4. Fittings Test
I tested various fittings to determine their maximum leak rate which include, 1/4” & 3/8” KC
fittings, 1/4” Swagelok, and 1/4" & 1/2” VCR. By using the helium bag technique on the helium
mass spectrometer, I lined up each fitting to have 9 nodes for one test, then 18 nodes for a second
test to compare any discrepancies with added fittings. Testing is still in process, but some results
have shown that the fittings with 18 nodes have a lower leak rate by almost a magnitude. The
helium bag technique is putting a bag over the test samples and pumping helium into the bag.
Helium has atoms small enough to enter through exposed crevices that cannot be seen to the
human eye. The mass spectrometer creates a vacuum within the sample which creates a low
pressure system. The helium within the bag will be wanting to be pumped into the sample do to
its high pressure property. Problems that I have faced with this test is issues with ventilations. To
run the next test, I would need the room to vent out any lingering helium in the air. This can
potentially take many hours causing data to be inaccurate.
3.5. Web Page
I developed a Hazardous Gas Leak Detection Specifications and Standards webpage. This
included industry standards (ASTM standards, ASME standards, IEEE standards, etc), military
standards, and NASA standards. I provided the number, title, and hyperlink for full disclosure
and quick access of the documents. Prior to the webpage, these documents were disorganized
and under no subfolders for organization. After completion of the webpage, documents could be
easily searched and added without further complications to the organization. Each document title
is hyperlinked to ASTM procedure PDFs which will be used for further leak detection tasks.
3.6. Conclusion
In 10 weeks I was able to learn an abundant amount of information on leak detection from
reading procedures, manuals, performing tests, and building equipment. I found that my results
for each task have been precise to predicted measurements, hence successful experiments. Final
test results will be used to help improve overall equipment testing and troubleshooting
operations. The Leak Tester Cart will be used to detect other equipment for leak integrity and the
tightly sealed fittings test will be vital for understanding a system’s internal leak rate.

6. 4.Acknowledgments
I would like to thank Billy Mitchell for guiding me and teaching me the fundamentals of leak
detection; Richard Arkin for answering any questions and providing manuals and guides needed
for me to succeed during this internship; Guy Naylor for leading me through the lab and
providing necessary help in troubleshooting with whatever task was at hand; lastly, the entire
Hazardous Gas Leak Detection Subsystem team for making my internship at the Kennedy Space
Center a memorable experience.