Droplet Dual-Column CCN User manual

Dual-Column Cloud
Condensation Nuclei
Counter
Operator Manual
for Dual-Column CCN
DOC-0128 Revision F
2400 Trade Centre Avenue
Longmont, CO 80503 USA

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© 2017 DROPLET MEASUREMENT TECHNOLOGIES
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All rights reserved. No part of this document shall be reproduced, stored in a retrieval system, or
transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without
written permission from Droplet Measurement Technologies. Although every precaution has been
taken in the preparation of this document, Droplet Measurement Technologies assumes no
responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the
use of the information contained herein.
Information in this document is subject to change without prior notice in order to improve accuracy,
design, and function and does not represent a commitment on the part of the manufacturer.
Information furnished in this manual is believed to be accurate and reliable. However, no
responsibility is assumed for its use, or any infringements of patents or other rights of third parties,
which may result from its use.
Trademark Information
All Droplet Measurement Technologies product names and the Droplet Measurement Technologies
logo are trademarks of Droplet Measurement Technologies.
All other brands and product names are trademarks or registered trademarks of their respective
owners.
Warranty
The seller warrants that the equipment supplied will be free from defects in material and
workmanship for a period of one year from the confirmed date of purchase of the original buyer.
Service procedures and repairs are warrantied for 90 days. The equipment owner will pay for shipping
to DMT, while DMT covers the return shipping expense. Consumable components, such as tubing,
filters, pump diaphragms, and Nafion humidifiers and dehumidifiers are not covered by this warranty.
Software Licensing Agreement
DMT licenses CCN software only upon the condition that you accept all of the terms contained in this
license agreement. This software is provided by DMT “as is” and any express or implied warranties,
including, but not limited to, the implied warranties of merchantability and fitness for a particular
purpose are disclaimed. Under no circumstances and under no legal theory, whether in tort, contract,
or otherwise, shall DMT or its developers be liable for any direct, indirect, incidental, special,
exemplary, or consequential damages (including damages for work stoppage; computer failure or
malfunction; loss of goodwill; loss of use, data or profits; or for any and all other damages and losses).
Some states do not allow the limitation or exclusion of implied warranties and you may be entitled
to additional rights in those states.

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Laser Safety
The following warning label appears at the base of the CCN-200 back panel, near the OPCs:
Great care must be taken to avoid exposure to the laser, Do not remove protective barriers.
CAUTION: Use of control or adjustments or performance of procedures other than specified in this
manual may result in hazardous radiation exposure.
WARNING!
Use extreme care in preventing water from entering the inlet to the DUAL COLUMN CCN counter.
Water entering the inlet will wet the temperature sensor, causing erratic readings and throw the
entire temperature control system off.
In addition, liquid water will plug the sheath air filter and shut off flow.
If liquid water does enter the inlet:
IMMEDIATELY SHUT OFF THE INSTRUMENT.
If a small amount of water (fewer that cc or less) has entered, disconnect the pressure transducer
and sample inlet fittings from the inlet manifold and dry the manifold using warm air and replace
the filter on the sheath air.
If additional water has entered the system contact
Droplet Measurement Technologies immediately.
WARNING!
The DUAL COLUMN CCN Counter must be prepared for shipping by drying the
column and draining the OPC (see Section 10.0).

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CONTENTS
1.0 Setting up the Dual-Column CCN (CCN-200)....................................................... 8
1.1 Unpacking.............................................................................................................................. 8
1.2 Connecting the Instrument Components.............................................................................. 9
1.3 USB Memory Stick............................................................................................................... 11
1.4 Setting the Flow and Humidifying the CCN-200.................................................................. 12
1.5 Checking out the CCN-200 .................................................................................................. 14
1.5.1 Zero-Count Test ............................................................................................................. 14
1.5.2 Counting Test ................................................................................................................ 15
1.5.3 Leak Test (for Dual CCNs Installed in Pressurized Aircraft) ........................................... 16
2.0 Installation.......................................................................................................18
2.1 Mounting Considerations.................................................................................................... 18
2.2 Power Supply Considerations.............................................................................................. 18
3.0 Product Description .........................................................................................19
3.1 Introduction......................................................................................................................... 19
3.2 CCN-200 Specifications........................................................................................................ 20
3.3 Operating Limits .................................................................................................................. 22
4.0 Theory of Operation.........................................................................................22
4.1 How the CCN Generates Supersaturation........................................................................... 22
4.2 Details of CCN Design .......................................................................................................... 23
4.3 Instrument Components ..................................................................................................... 24
4.4 Air and Water Flows............................................................................................................ 28
4.4.1 Sample and Sheath Air Flows ........................................................................................ 30
4.4.2 How the System Maintains Pressure and Removes Excess Water ................................ 30
5.0 Power and Communication Connections ..........................................................32
6.0 Printed Circuit Boards ......................................................................................34
7.0 CCN Maintenance ............................................................................................37
7.1 Every 2 Days / Before Every Flight ...................................................................................... 37
7.2 Every Month........................................................................................................................ 37
7.3 Every Three Months ............................................................................................................ 37
7.4 Every Year............................................................................................................................ 38
7.5 Pump Diaphragm and Motor Maintenance Requirements ................................................ 38
8.0 Calibration Procedures .....................................................................................39
8.1 SS% Calibration.................................................................................................................... 39
8.1.1 Recommended Calibration Equipment.......................................................................... 39
8.1.2 SS% Calibration Procedure ............................................................................................ 40
8.2 Flow Calibrations................................................................................................................. 41
8.2.1 Recommended Calibration Equipment.......................................................................... 41
8.2.2 Flow Calibrations Procedure.......................................................................................... 42
8.3 Pressure Calibration ............................................................................................................ 45
8.3.1 Recommended Calibration Equipment.......................................................................... 45
8.3.2 Pressure Calibration Procedure..................................................................................... 45
8.4 OPC Calibration ................................................................................................................... 45
8.4.1 Recommended Calibration Equipment.......................................................................... 45
8.4.2 OPC Calibration Procedure ............................................................................................ 46
8.4.3 OPC Cleaning Procedure................................................................................................ 46

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9.0 Troubleshooting .............................................................................................. 50
10.0 Preparing the CCN for Shipping........................................................................ 57
10.1 Dual Column CCN Drying Procedure Prior to Shipping ....................................................... 57
10.2 Repacking for Shipping ........................................................................................................58
PART II: CCN-200 Software............................................................................................ 59
11.0 Product Description......................................................................................... 59
11.1 Introduction......................................................................................................................... 59
12.0 Dual CCN.exe (Main Program) ......................................................................... 60
12.1 Common Indicators (Appear on all CCN-200 Tabs).............................................................61
12.2 Column Controls.................................................................................................................. 61
12.2.1 SS (Supersaturation) Settings Tab ................................................................................. 62
12.2.2 Temps Tab (Temperatures) ........................................................................................... 65
12.2.3 Flows Tab....................................................................................................................... 68
12.2.4 OPC Tab (Optical Particle Counter) ............................................................................... 70
12.2.5 Monitor Tab (Alarm Monitoring)................................................................................... 72
12.2.6 Prog Control Tab............................................................................................................ 74
12.2.7 Chart Tab ....................................................................................................................... 75
12.3 Histograms...........................................................................................................................76
12.4 Time-Series Charts............................................................................................................... 76
12.5 Serial Output Tab.................................................................................................................77
12.6 DMT Tab (Accesses Service Tabs)........................................................................................ 78
12.7 Program Input Files ............................................................................................................. 84
12.8 Program Output Data ..........................................................................................................85
12.8.1 Serial Stream ................................................................................................................. 85
12.8.2 Output Files ................................................................................................................... 87
13.0 SS Settings Config Editor.................................................................................. 89
14.0 CCN Calibration Editor.exe............................................................................... 90
14.1 Standard Screen .................................................................................................................. 91
14.2 Screen with DMT Settings ...................................................................................................92
15.0 Dual CCN Playback.exe .................................................................................... 94
15.1 Changing the Current Time .................................................................................................95
15.2 Selectable Chart Options..................................................................................................... 96
16.0 Chart Options (for Dual CCN.exe and CCN Playback.exe Programs)................... 96
17.0 Remote Operation of CCN Programs through Remote Desktop ........................ 97
17.1 Shutting Down the CCN-200................................................................................................99
Appendix A: Glossary.................................................................................................. 100
Appendix B: Relationship between SS%, Particle Concentration, and Percentage of CCN
Counted...................................................................................................................... 105
Appendix C: Assy, Cable 28V Power ............................................................................ 106
Appendix D: Dual CCN Mounting Hole Locations ......................................................... 107
Appendix E: Further Resources.................................................................................... 108
Appendix F: CCN-200 Aircraft Inlet .............................................................................. 108
Appendix G: Sheath Flow Filter Testing and Replacement............................................ 109
18.0 Appendix H: CCN Accessories......................................................................... 110
18.1 Spares and Consumable Supplies...................................................................................... 110
Appendix I: Revisions to Manual ................................................................................. 111

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Figures
Figure 1: Dual CCN with Shipping Hood, Pallet and Fitted Case........................................ 8
Figure 2: Bottle Hold-Down Clamp .................................................................................10
Figure 3: USB Memory Stick...........................................................................................11
Figure 4: SS Tab with Dry Start Up and Dry Shut Down Buttons Active............................12
Figure 5: Drying System Time Switch (in Center, Circled) ................................................13
Figure 6: Green Status Light ...........................................................................................14
Figure 7: Connecting Inlet A to Inlet B with Tubing.........................................................16
Figure 8: Vents Connected to Bottle Caps (for Aircraft Operation) ..................................18
Figure 9: CCN-200 with Front-Mounted Touch Screen ....................................................19
Figure 10: Supersaturation Being Generated in the CCN Column .......................................
Figure 11: Side View of CCN with Important Components Labeled..................................24
Figure 12: Traps and Pumps ...........................................................................................25
Figure 13: TEC Current Controllers .................................................................................26
Figure 14: Sheath Flow Filters and Frits..........................................................................27
Figure 15: Proportional Valves .......................................................................................27
Figure 16: Air and Water Flow for Column A ..................................................................28
Figure 17: Air and Water Flow for Column B...................................................................29
Figure 18: Location of Power, Communications, Sample and Exhaust Connections .........32
Figure 19: Power Supply and Controller Boards with Important LEDs Identified..............34
Figure 20: CDPE Board. D1, D2, and D3...........................................................................35
Figure 21: Power Supply Boards for TEC Current Control Module, with LED Circled.........36
Figure 22: OPC Board.....................................................................................................36
Figure 23: Calibration Set-Up .........................................................................................39
Figure 24: Activation Curve Used in SS% Calibration.......................................................40
Figure 25: Temperature Gradient Curve for Different SS% ..............................................41
Figure 26: Sheath Flow Metering Valves ........................................................................42
Figure 27: Entering Values in the Calibration Spreadsheet for Regression Analysis .........43
Figure 28: Sheath Flow Calibration Spreadsheet.............................................................44
Figure 29: OPC 1st Stage Monitor Voltage......................................................................46
Figure 30: Column A’s Beam Dump and Set Screws. Column B has an Identical OPC. ......47
Figure 31: Air Drying OPC with Canned Air .....................................................................48
Figure 32: OPC Assembly, Exploded View.......................................................................49
Table 1: Dual Column CCN Fuse Listing...........................................................................52
Figure 33: Nafion Insertion ............................................................................................54
Figure 34: Typical Healthy Membrane............................................................................54
Figure 35: Typical Bad Membrane Note Kinks and Flat spots ..........................................54

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Figure 36: CCN-200 Window Quadrants......................................................................... 60
Figure 37: Indicators Visible on all CCN-200 Tabs ........................................................... 61
Figure 38: SS Settings Tab ............................................................................................. 62
Figure 39: Dry Start Up and Dry Shut Down Buttons ...................................................... 62
Figure 40: Supersaturation (SS) Settings Tab Display in Manual SS Mode....................... 64
Figure 41: SS Tab in Manual SS Mode with Delta T selected as Manual Input ................. 64
Figure 42: Temperature Tab Screen Shows Temp Set Points and CCN Temperatures ...... 65
Figure 43: Flows Control Tab ......................................................................................... 68
Figure 44: Optical Particle Counter Tab ......................................................................... 70
Figure 45: Monitor Tab ................................................................................................. 72
Figure 46: Prog Control Tab........................................................................................... 74
Figure 47: Watch Dog Light ........................................................................................... 75
Figure 48: Chart Tab...................................................................................................... 75
Figure 49: Histograms ................................................................................................... 76
Figure 50: Flow A Chart ................................................................................................. 76
Figure 51: Serial Output Tab in "Normal" Mode ............................................................ 77
Figure 52: DMT Service Tab........................................................................................... 78
Figure 53: Text Box for Entering Password to Access DMT-Service Tab........................... 78
Figure 54: DMT Service Tab – PID Sub-Tab..................................................................... 79
Figure 55: DMT Service Tab – Offset & Gains Sub-Tab.................................................... 81
Figure 56: DMT Service Tab – Flow Calib. Sub-tab.......................................................... 82
Figure 57: DMT Service Tab – Error Sub-Tab .................................................................. 83
Figure 58: DMT Service Tab – Timing Sub-Tab................................................................ 84
Figure 59: Program for Setting the Supersaturation Tables ............................................ 89
Figure 60: CCN Calibration Editor.exe ............................................................................ 91
Figure 61: CCN Calibration Editor.exe with DMT Tabs.................................................... 92
Figure 62: CCN Data Playback........................................................................................ 94
Figure 63: Playback Speed Control ................................................................................ 95
Figure 64: Playback Timing Controls .............................................................................. 95
Figure 65: Using Playback Controls for Zooming ............................................................ 95
Figure 66: Selectable Chart Control Panel...................................................................... 96
Figure 67: Shutdown Button ......................................................................................... 99
Figure 68: Percentage of CCN Counted vs. Particle Concentration for Different SS%..... 105

1.0 Setting up the Dual-Column CCN (CCN-200)
Several steps are required for initial CCN-200 set-up:
•Unpacking and mounting the instrument
•Connecting CCN components such as the power cables, supply and drain bottles, and touch
screen monitor
•Setting the flow and humidifying the instrument (humidification can take up to 12 hours and
must be performed every time the CCN is dry when started)
•Checking that the CCN is functioning properly
The following sections describe these steps in detail.
Any time the CCN is shipped, it must be dried out and properly repacked prior to shipment. Failing to
follow proper procedure will result in damage to the instrument. See section 10.0 for details on
drying out and packing the instrument.
1.1 Unpacking
To minimize the potential for damage in shipping, the Dual Column CCN arrives on a 36” x 36” pallet
with a fitted case, special frame and protective hood (Figure 1). The frame can be substituted as a
bench stand for the unit.
Figure 1: Dual CCN with Shipping Hood, Pallet and Fitted Case

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1) Cut straps securing case to pallet and save pallet.
2) Lift the Dual CCN unit out of the case, using the back bar on the stand as a handle.
3) Remove two bolts on the underside of the hood. These bolts go through an angled aluminum
bracket into the upright side of the frame, and there will be one bolt on either side.
4) Hold the shipping hood and pull up the two head bolts that go through the aluminum strap
into the frame. The bolts are essentially pins that can be pulled straight up.
5) Inspect the CCN for shipping damage.
6) If the CCN is to be mounted in a different rack, remove the CCN from frame.
7) Save parts for return shipping.
8) Next, connect the instrument components as described below.
1.2 Connecting the Instrument Components
1) Connect the power cable to the instrument. The power cable (ASSY-272) supplied in the
startup kit is already installed and pretested on the bench top AC/DC power supply, which is
also in the kit. The white wire (labeled “+28V”) connects to +28V VDC and the black wire
(labeled “RETURN”) connects to the return of the power supply. If a longer cable is being
used, refer to Appendix C. Check polarity of the power before connecting the instrument.
2) Unpack the supply bottle, drain bottle, bottle-hold down clamp and clamp screw. These are
packed separately from the main Dual Column CCN instrument. The supply and drain bottle
caps have been packaged in a plastic bag and tied to the frame. Remove the tie and bag.
3) Install the drain bottle in the bottle holder. The best location for the drain bottle is in the rear
of the bottle tray. See Figure 2.
4) Fill supply bottle with distilled or deionized water and set it in the front of the bottle tray.
5) For airborne applications, install the bottle hold-down clamp. Figure 2 shows the hold-down
clamp on a CCN-100 instrument; the clamp is identical on the CCN-200.
WARNING!
The DUAL COLUMN CCN COUNTER is not reverse polarity protected and will be significantly
damaged by incorrect wiring. Make sure the CCN Main Power is OFF prior to connecting or
disconnecting any external power or I/O Cable.

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6) If desired, mount the touch screen to the front of the CCN case:
a. Remove the instrument’s front cover. There will be 12 screws around the perimeter
of the instrument, and three on the left side into the connection panel. Once these
screws are removed, the instrument cover can be lifted off.
b. Remove the two Phillips-head screws that hold the tripod leg to the back of the
screen. This will expose the back of the screen and the location of the four mounting
holes.
c. Remove the four hole plugs from the front of CCN case.
d. Connect the cables to the screen.
e. Mount the screen to the case, using the four 4.7 mm screws with lock washers that
are provided in the startup kit.
f. Save the parts that were removed from the screen and the case.
g. Put the cover back on the instrument.
7) Connect the touch-screen video and serial cables to the side panel. Turn on power to the
touch screen either from the external power supply or from the side panel, using the cable
provided.
8) Remove plugs from inlet and outlet fitting on the side of the unit.
9) Proceed to the following section.
Figure 2: Bottle Hold-Down Clamp

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1.3 USB Memory Stick
A USB memory stick is located inside the CCN-200 frame (Figure 3). This memory stick should be kept
in this location, as it contains important information about the instrument:
•White papers describing the theory behind the CCN design
•A copy of the CCN-200 manual
•Detailed spreadsheets for use in instrument calibration
•LabVIEW software programs used to operate the CCN-200
Figure 3: USB Memory Stick

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1.4 Setting the Flow and Humidifying the CCN-200
1. If you have not already done so, install the drain and supply bottles on the CCN. The supply
bottle should be filled with distilled or deionized water.
2. Start the CCN-200. The breaker on the side panel also serves as the power switch. The
computer will load the Dual CCN.exe control program and start automatically.
3. During the first 20 seconds after the program starts, click the Dry Start Up button shown in
Figure 4. (Note: by default, the Dry Start Up and Dry Shut Down buttons disappear after 20
seconds, but the user can configure this time setting using the SS settings Config Editor
program.(See Section 13.0.) Selecting Dry Start Up will set the liquid supply pump to high
and disable the CCN concentration alarm.
4. On the main CCN window, go to the Flows tab.
5. The flow ratio between the sheath and sample flow is displayed directly in the center
window. Adjust the green knobs on the sheath flow metering valves (See Figure 26) until
these ratios read 10.0 +/- 0.3.
Figure 4: SS Tab with Dry Start Up and Dry Shut Down Buttons Active

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6. Check the position of the OPC drying system time switch. This switch controls the solenoid
pump in the drying system. The switch is labeled SW1 and is located in the middle of the
Controller Printed Circuit Board, as shown in Figure 5 The solenoid pump can cycle every 2
seconds or every 16 seconds. Set this switch to the 16-second position.1
1In general, the switch should be set to the 16-second position, because when the pump operates every
2 seconds water may infiltrate the CCN without generating an alarm. However, the 2-second position is
recommended in certain circumstances. It is useful in airborne applications where altitude changes can
cause migration of saturated water vapor into the OPC. In addition, if the OPC has fogged, switching to
the 2-second position will speed the removal of water vapor. (The switch should be returned to the 16-
second position after the fog has dissipated.) For more details on the OPC drying system, see section 10.1.
Figure 5: Drying System Time Switch (in Center, Circled)

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7. After the column is fully wetted, the OPC should be counting. Note that it may take 4 to 12
hours for the CCN-200 to become properly humidified and count particles. At this time, the
status light in the upper center of the window should be green (Figure 6). A green status light
indicates the Dual CCN Instrument is functioning properly. You can now begin to collect data.
If the status light is yellow or red, copy the latest data file from C:\CCN DATA. Shut off
power to the CCN instrument and send the data file to DMT at:
[e-mail].
1.5 Verify the CCN-200 has been set-up correctly
Before performing the tests below, ensure the instrument is properly set up and humidified. See
previous sections for instructions. At this point, the OPCs should be counting and the status light
should be green.
1.5.1 Zero-Count Test
Locate the filter with part number FLTR-0022, which included in start-up kit. For each column,
perform the zero-count test as follows:
1) Install the filter on the inlet while the instrument is running.
2) Wait 15 minutes for system to clean out. Counts should now be less than five per second.
Figure 6: Green Status Light

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1.5.2 Counting Test
For each column, perform the counting test as follows:
1) Connect a volume displacement flow meter (Gilian, Buck, or laboratory constructed) to the
inlet of the CCN-200.
2) Note the total flow on the Flows tab.
3) Measure the flow with the displacement flow meter.
4) Repeat step 4 five times. The average measured flow should be ±10% of the stated flow on
the Flows tab.
5) Remove the filter from the inlet of the CCN and set the following supersaturation gradient
scans:
Supersaturation Setting
Duration of Scan
0.2% 10 minutes
0.4%
5 minutes
0.6% 5 minutes
0.8%
5 minutes
1.0%
5 minutes
Run two complete supersaturation cycles. As the supersaturation increases, verify that the
number concentration of particles measured remains stable or increases.
6) Repeat the above procedure for both columns. The concentrations for the two columns
should not differ by more than 15% for the same supersaturation setting and sample source.

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1.5.3 Leak Test (for Dual CCNs Installed in Pressurized Aircraft)
If CCN-200 unit will be installed in pressurized aircraft, perform the following leak test in addition to
the zero-count.
1) Install a loop of tubing between inlet A and inlet B (Figure 7
Figure 7: Connecting Inlet A to Inlet B with Tubing
2) Install a valve or plug on the inlet A while the instrument is running. (Note: Only Column A
has a sample pressure sensor, so do not install the plug on Column B.)
3) Allow the unit’s internal air pump to evacuate the system. This may take several minutes.
Monitor the progress on the Flows tab Sample Pressure field.
4) When the unit has pumped down below approximately 400 mb, go into the Flows tab and
turn off the Air Pump. This will turn off power to the pump, which will also act as a seal.
5) If unit does not pump down below 400 mb, there is a leak that needs to be fixed prior to
retesting.
6) Wait 60 seconds to allow pressure to stabilize, and then monitor how fast the sample
pressure rises. Typically 5 mb or less per second is good.
7) If unit leaks at an unacceptable rate, try isolating and fixing leak then retest using above
method.
8) To shut down the CCN-200, always start by shutting down Dual CCN.exe. Go to the Prog Control
tab and press the Shutdown button. You can then simply turn off the main power switch on the
side of the unit. You can also close Windows first by turning off the computer and then turning off
the power switch on the side of the unit when the screen goes blank.

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If a leak or other problem is suspected, copy the latest data file from C:\CCN DATA. Shut off power
to the CCN instrument and send the data file to DMT at [e-mail].
WARNING!
Use extreme care in preventing water from entering the inlet to the CCN counter. Liquid water
will plug the sheath air filter and shut off flow. If liquid water does enter the inlet:
IMMEDIATELY SHUT OFF THE INSTRUMENT.
If a small amount of water (less than a few ccs) has entered, disconnect the pressure transducer
and sample inlet fittings from the inlet manifold and dry the manifold using warm air and replace
the filter on the sheath air.
If additional water has entered the system,
contact Droplet Measurement Technologies immediately.
WARNING!
The CCN Counter must be prepared for shipping by drying the column and draining the OPC.

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2.0 Installation
The CCN-200 is designed for ground-based or airborne applications. The entire sampling system is
sealed on the CCN-200 so that it can be used on a pressurized aircraft as long as the sample air inlet
and outlet are at ambient pressure. For aircraft operation, the vents must be reconnected to the
bottle caps (Figure 8).
Figure 8: Vents Connected to Bottle Caps (for Aircraft Operation)
2.1 Mounting Considerations
Refer to Appendix D for mounting hole locations. The CCN-200 must always be mounted in an upright
configuration. The back panel is the structural component of the CCN-200 and is a 1/8-inch, 6061-T6
aluminum plate. All of the major internal components mount with stainless steel fasteners to this
aluminum plate, and critical mounting screws have helicoil inserts for strength.
For best performance, the environmental temperature of the CCN-200 should be kept as low as
possible without freezing. For more details, see section 3.3 “operating limits”.
2.2 Power Supply Considerations
The CCN-200 is designed to operate on 28 VDC power. Ground-based applications require a line
voltage to 28 VDC supply, which can be either a linear or switching supply. The capacity of the supply
should be at least 25 A. The CCN-200 may draw this current load for up to a few minutes at startup,
and then will typically draw 20 A in normal operation.
If there are high frequency spikes when the 400 Hz power is converted to 28 VDC, this can cause
problems with the CCN-200. If problems occur when operating the CCN-200 in an aircraft
environment, check the line voltage to 28 VDC supply. A 28 VDC aircraft cable with a filter is included
and should be used for aircraft operation.

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3.0 Product Description
3.1 Introduction
The CCN-200 (Figure 9) is based on the design of Dr. Greg Roberts of Scripps Institute of
Oceanography. Dr. Athanasios Nenes of Georgia Institute of Technology did the CCN-200’s
theoretical parameterization. The technology is patented, and Droplet Measurement Technologies
possesses the exclusive license to manufacture the instrument.
Figure 9: CCN-200 with Front-Mounted Touch Screen

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3.2 CCN-200 Specifications
Technique
Activation of CCN particles at constant supersaturation
maintained in two simultaneously operating, 50-cm-high
columns with continuously wet
ted walls and longitudinal
thermal gradients;2
sizing of the activated droplets using
two optical particle counters
Aerosol Medium
Air, 5 - 40 °C (41 – 104 °F)
Number Concentration Range
Depends on supersaturation:
•6,000 particles/sec at supersaturations below 0.2%
•20,000 particles/sec at supersaturations above 0.3%
Measured Particle Size Range
(from OPC, after supersaturation)
0.75 – 10 µm
Supersaturation Range
0.07 – 2.0%
Time Required for Supersaturation Change
~30 seconds for 0.2% change
Maximum number of automatically scanned
supersaturation settings
250
Optical Particle Counter Laser
660 nm, 35 mW
Flow Range
•Total flow: 200 – 1000 volume cc/min (factory calibrated
at 500 Vccm)
•Sample flow: 20 – 100 Vccm
•Sheath flow: 180 – 900 Vccm
Flow Control
•Total flow is adjustable from within CCN Counter
software
•
Sample/Sheath flow ratio is adjustable using manual
metering valve
Pump
Solenoid pumps for water; diaphragm pump for air
Routine Maintenance
Every Four Days/Before Every Flight
•Empty and refill water bottles
•
Check OPC water trap and bottom of case for water
leakage.
Monthly:
•Check air inlet filters on cover
•Check flow calibration
•Check desiccant tube
Every Three Months:
•Replace sheath flow filter
Recommended Service
Annual cleaning and calibration at DMT service facility
Front Panel Display
Computer monitor
2Within each column, the supersaturation is constant. However, the two columns can maintain different
supersaturation rates.