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Related Manuals for Droplet UHSAS
Summary of Contents for Droplet UHSAS
- Page 1 Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 0.06 – 1.0 microns Operator Manual DOC-0210 Rev E-4 Software Version 4.1.0 2400 Trade Centre Avenue Longmont, CO 80503 C O P Y R I G H T © 2 0 1 7 D R O P L E T M E A S U R E M E N T T E C H N O L O G I E S...
- Page 2 Droplet Measurement Technologies, Inc. Although every precaution has been taken in the preparation of this document, Droplet Measurement Technologies, Inc. assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.
- Page 3 STRICT OBSERVANCE OF THE FOLLOWING LASER SAFETY LABELS IS ADVISED. The UHSAS is a Class I Laser Product with an embedded Class 4 pump laser. CAUTION: Use of control or adjustments or performance of procedures other than specified in this manual may result in hazardous radiation exposure.
- Page 4 Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Pump Laser Main Laser Wavelength ~797 nm ~1054 nm Maximum power 1.6 W - 50 mW for leakage through mirror - 1100 W for recirculating power Maximum exposure time - 1/10 second for 50 mW...
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Page 5: Table Of Contents
ADCs and Peak Height Analysis ................17 2.4.2 Monitoring and Control ................... 18 On-board PC ........................19 Unpacking and Setting up the UHSAS ............19 Using the Instrument ................... 21 Start-Up .......................... 21 Shutdown / Power Off Procedure ................. 25 Calibration .................... - Page 6 Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 5.2.3 Step Two: Absolute Calibration ................30 Calibration Confirmation ....................32 5.3.1 Particle Size Calibration Confirmation ..............32 5.3.2 Flow Rate Calibration Confirmation ................ 32 Safety Procedures and Troubleshooting ............33 Safety Procedures ......................33 Troubleshooting ......................
- Page 7 Figure 20: Opening the Exhaust Line ................36 Figure 21: UHSAS Power Switch on Front of Unit ............36 Figure 22: UHSAS Laser Interlock Switch on Rear of Unit ..........37 Figure 23: Unscrewing Cleaning Port ................. 38 Figure 24: Cleaning the Optic..................38 Figure 25: Map Tab ....................
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Page 8: Part I: Hardware
The UHSAS is also available as an airborne instrument. Both airborne and ground-based versions can be ordered with two additional features: bidirectional and particle-by-particle capabilities. The bidirectional feature allows another computer to have limited control of the UHSAS and use the instrument to acquire data. The particle-by-particle feature allows the UHSAS to generate additional output data, specifically information on the size and inter-particle time of individual particles. -
Page 9: Specifications And Features
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 1.2 Specifications and Features Technique: Aerosol spectrometry Temperature Auxiliary Parameters: Pressure Derived Parameters: Particle diameter Number Concentration Range: 3,000 per second Particle Size Range: 0.06 – 1 µm Aerosol Medium: Air, 0 - 30 °C (32 - 86°F) Counting Efficiency: •... -
Page 10: Electrical Specifications
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 1.3 Electrical Specifications Power Requirements: 100-240 VAC, 47-63 Hz, 200W Fuse: BUSS fuse, GMA-2A 1.4 Physical Specifications Size: 56 x 43 x 24 cm Weight: 31 kg 1.5 Operating Limits Temperature: 0 to 30 °C... -
Page 11: Theory Of Operation
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Theory of Operation The instrument’s laser illuminates particles, which scatter light. The system captures the peak light signals that are generated. These signals are used for particle sizing, since the amount of light scattered correlates strongly with particle size. -
Page 12: Optical System
The imaging optics have an acceptance aperture of 23 mm diameter at a distance of 8 mm from the interaction region. The Mangin reflectors are aluminum coated with reflectivity of 0.9. In addition to the primary and secondary detection systems, the UHSAS has a reference detector. This detector serves as a reference for changes in laser power. -
Page 13: The Mechanical Housing
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 2.1.3 The Mechanical Housing The laser and detection optics are built into the optical block, which is a sealed mechanical enclosure. See the following figures. Figure 3: Side View of Optical Block Figure 4: Light Collection Angles DOC-0210 Rev E-4 ©... -
Page 14: Figure 5: Top View Of Optical Block
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Figure 3 and Figure 4 show two views of the optical cavity. Figure 3 shows the general layout of the aerosol inlet, placement of the solid state laser and particle stream with respect to the mangin mirror pair. -
Page 15: Flow System
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 2.2 Flow System A pump draws on an exhaust jet, pulling flow through the inlet jet and across the laser mode as illustrated in Figure 6. The inlet jet is an aerodynamically focused assembly with a sample nozzle of 500 µm diameter and a sheath nozzle of 760 µm diameter. -
Page 16: Analog Electronics
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 2.3 Analog Electronics 2.3.1 Particle Signal Amplification and Tracking The detector photodiodes produce a photocurrent, which the analog chain then converts to a voltage. The system then processes the resulting signal, which is called the particle signal. The chain is repeated for the primary and secondary detection systems. -
Page 17: Laser Power Monitoring
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 2.3.2 Laser Power Monitoring The reference detector is used as a voltage reference and automatic gain control. It is also used for monitoring laser output power, which is directly proportional to the laser cavity power. As the laser power drifts, the instrument maintains calibration. -
Page 18: Monitoring And Control
The look-up table is the crux of the peak-height analysis in the UHSAS. The user can reset this table at any time to generate a new bin mapping. Using the relative gains and the calibration curve and points, the instrument automatically converts the bin boundaries to a mapping of voltages at each of the gain stages. -
Page 19: On-Board Pc
Unpacking and Setting up the UHSAS The UHSAS instrument is delivered in a shipping case that contains the necessary cables and other equipment to make the instrument functional. The power cable, keyboard, and mouse for the instrument are located in a pouch in the lid of the box. -
Page 20: Figure 9: Extra Tubing On Inlet Line
5) Connect the power cable to the wall power outlet. Input power to the instrument can range from 100-240 VAC 50/60Hz. 6) Connect the UHSAS instrument to an Ethernet network, if desired. The connector (RJ-45 female) for that cable is located on the back of the instrument. -
Page 21: Using The Instrument
2) Turn on the instrument with the power switch located on the back panel. 3) Click on the Spectrometer icon on the desktop to bring up the UHSAS window, shown in Figure 10. Note that the program starts with the Controls tab as the default. The Controls screen allows the user to set the sample flow and to monitor various parameters. -
Page 22: Figure 10: The Controls Tab On The Uhsas Software
2) Look to see that the Sheath flow is about 500-800 sccm (700 sccm is typical at sea level). Figure 10: The Controls Tab on the UHSAS Software DOC-0210 Rev E-4 © 2017 DROPLET MEASUREMENT TECHNOLOGIES... -
Page 23: Figure 11: Zero Filter On Top Of Uhsas Unit
4.3 Perform a Zero-Count: 1) Ensure the zero-count filter is in place, as shown in Figure 11. Figure 11: Zero Filter on Top of UHSAS Unit 2) Select the Histogram tab to display counts versus bin number. 3) Click on the Run button near the upper left corner of this window to show the particle accumulations. -
Page 24: Figure 12: 100-Nm Particle Distribution On A Properly Calibrated Instrument
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Figure 12: 100-nm Particle Distribution on a Properly Calibrated Instrument Figure 13: 100-nm Particle Distribution on an Instrument that Needs Calibration 3) Sample the ambient air. The histogram distribution should show a smooth transition of particle counts from small to large bins (Figure 14.) Small “bumps”... -
Page 25: Shutdown / Power Off Procedure
2) Put the zero filter on the inlet line. 3) Press the rectangular STOP button located in the upper right of the UHSAS screen. This stops the execution of the UHSAS program. Note that you cannot quit by clicking the DOC-0210 Rev E-4 ©... -
Page 26: Calibration
Calibration 5.1 Calibration Overview Calibration is an important process for any particle spectrometer. The UHSAS, with its high resolution and large number of arbitrarily settable bins, poses unique challenges in this area. Several features have been added to this instrument to make the calibration process as easy and accurate as possible. -
Page 27: Figure 16: Example Calibration Curve
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) instrument is 1054 nm, it is expected that all particles below approximately 300 nm will lie on a sixth-power curve—that is, the particle signal is a sixth-power of the particle size. This has been hard-coded into the instrument by forcing the signals from G3, G2 and G1 to fall on a sixth- power curve. -
Page 28: Calibration Procedure
• • Improved empirical data on the non-power-law portion of the curve It may also be necessary to recalibrate the size scale of the UHSAS. Some reasons for this include: • The laser power has dropped and cannot be fully restored Internal relative calibration has degraded •... -
Page 29: Figure 17: Running A Relative Gain Calibration
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 2) Ensure the Reference value is 1.75 – 2.75 V (see the Controls tab). 3) On the Calibration tab, choose the relative gain tab labeled G3:G2 Gain and press Clear. 4) Open the sample inlet to ambient air in a normal lab environment (not a cleanroom environment). -
Page 30: Step Two: Absolute Calibration
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 6) Once the process stops, the graph should show the data points scattered around a best- fit line. 7) Repeat this procedure for the other relative gain tabs, which are labeled G2:G1 Gain and G1:G0 Gain. -
Page 31: Figure 18: Calibrating The Uhsas
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) With your collection of particles, note in which gain stage each particle will be measured by looking at the size of the particle and the calibration curve. The red dots on the calibration curve indicate the saturation levels of each gain stage—i.e., the largest particles measureable on each stage. -
Page 32: Calibration Confirmation
5.3.1 Particle Size Calibration Confirmation In order to confirm calibration of the UHSAS instrument, the following steps should be taken. 1) Confirm that the laser reference level and scattering level are at their original values. If they are not, cleaning may be needed; see section 7.0. -
Page 33: Safety Procedures And Troubleshooting
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) to describe the response of the flow controller. The parameters can be changed to accommodate other gases. Consult DMT for instructions or revised calibration parameters. Safety Procedures and Troubleshooting 6.1 Safety Procedures CAUTION: Do not operate laser with instrument cover off. -
Page 34: Manually Adjusting Flow Knobs
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) button, and commit a map with a range from 10 – 300 µs. The resulting histogram should show mostly particles with transit times of less than 100 msec. If there are many particles with longer transit times, check for leaks in the unit. -
Page 35: Maintenance
If this voltage drops by 25% or more, the laser optics will need to be cleaned. CAUTION: The UHSAS uses a high power invisible infrared laser. The optics should only be cleaned by personal familiar with laser safety precautions. Failure to follow safe practices can lead to eye damage or permanent blindness. -
Page 36: Figure 20: Opening The Exhaust Line
Lift the power interlock switch at the front corner of the unit and turn on the unit. Figure 21: UHSAS Power Switch on Front of Unit Ensure that the laser interlock switch at the rear is off by pressing it downward and allowing it to spring back to center. -
Page 37: Figure 22: Uhsas Laser Interlock Switch On Rear Of Unit
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Figure 22: UHSAS Laser Interlock Switch on Rear of Unit Turn the unit on and start the software program. Check the Laser Current reading on the Controls tab. It should read zero. If it does not, depress and release the laser interlock switch again. -
Page 38: Figure 23: Unscrewing Cleaning Port
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Locate the cleaning port for the mirror optic at the frontend of the optical block (i.e., the end near the computer display). Generally contamination occurs at the mirror end, so it is important to start cleaning with this optic. Remove the two lock-down screws near the cleaning port (Figure 23), then remove the cleaning port. -
Page 39: Communications
The serial port is determined by the Broadcast Port COM parameter on the Configuration tab. If this port is set to 0, no data are broadcast. See your IT support department for assistance with connecting the UHSAS to the local network or internet. DOC-0210 Rev E-4... -
Page 40: Part Ii: Software
UHSAS instrument. This manual describes version 4.1.0 of the software. When the UHSAS program is started, five tabs appear at the top of the screen. Clicking on these tabs will bring up different displays, as follows: 1) Controls Tab –... -
Page 41: Map Tab
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Map Tab The size range displayed on the histogram is controlled through the Map tab. The Map tab shows the boundaries of the bin width map that is used for the display. The map can be modified in multiple ways depending on user preference. -
Page 42: Figure 26: Map Tab With Password-Protected Options
Using the up and down arrows to change the values in the Minimum and Maximum fields. • Using the slider controls to change the minimum and maximum values. The blue portion of the slider bar shows the range that the UHSAS will map. DOC-0210 Rev E-4 © 2017 DROPLET MEASUREMENT TECHNOLOGIES... - Page 43 Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 3) Choose the number of bins. This can be done either by using the Bins slider control or by typing in a number in the field to the left of this slider. 4) Click on a Linear or Log bin spacing to create the bin map.
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Page 44: Histogram Tab
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 10.0 Histogram Tab This tab displays histograms, sets integration times, and initiates data logging. It is shown in Figure 27. Figure 27: Histogram Tab The slider bar on the top left of the screen allows the user to set the sample time. This determines the length of time over which counts are accumulated. -
Page 45: Autoscaling
10.1 Autoscaling The UHSAS software always autoscales the x axis. The y-axis is autoscaled by default, but can be fixed. For a fixed y-axis, right click in the graph and uncheck the “autoscale y” option. You can also reset the y-axis scale by typing directly into the axis labels. -
Page 46: Controls Tab
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 11.0 Controls Tab The Controls tab sets the sample flow and monitors other parameters including sheath flow, sample block temperature and pressure, and laser and cavity characteristics. The air flows are measured with electronic flow controllers or meters. - Page 47 Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) If a purge flow has been installed, the Purge monitor displays the purge flow, which should be 20 – 50 sccm. The purge flow provides fresh air for the optics and helps keep them clean.
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Page 48: Configuration Tab
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 12.0 Configuration Tab This tab displays the instrument configuration parameters. Note that some of these parameters are protected and cannot be changed unless the user logs in by typing a password in the Password field and then clicking on the Enter Password button. - Page 49 (The Map tab is the exception; it has its own Save button.) After configuring the UHSAS the way you want it, pressing Save on the Configuration tab will retain the settings you want.
- Page 50 Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) The Max Count field lists the maximum number of particles the UHSAS can process per second. At particle concentrations over this number, the instrument generates a warning and performance may be compromised. The Revision # lists the software revision number, while Version displays the firmware revision number.
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Page 51: Calibration Tab
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 13.0 Calibration Tab This tab performs the calibration functions of the instrument. It is only accessible when the user has logged on via the Configuration tab and the system is in calibration mode. There are several sub-tabs on this tab, which are described in the following sections. -
Page 52: Calibration Curve
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) 1.) Gain, the gain stage on which the particle signal appears 2.) mV, the signal size in mV of the particle signal 3.) nm, the size of the particle in nm. The Points field lists the element in the array that is currently being displayed. The array begins with element zero. -
Page 53: Control For Points Outside The Power-Law
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) The red cursor can be moved to see specific x and y coordinates on the curve. These appear as numeric values in the white field beneath the graph. 13.1.3 Control for Points Outside the Power-Law Above 300 nm, the calibration curve is defined by the calibration points specified in the lower left-hand corner of the screen. -
Page 54: Figure 31: A Relative Gain Sub-Tab
Run button again or until the instrument has processed the number of particles stipulated in the Pts control. The Pts control sets the number of particles the UHSAS processes before relative-gain calibration is complete. The Align button, visible only on the G2:G1 tab, is not used. -
Page 55: Appendix A: Output File Data Channels
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Appendix A: Output File Data Channels The UHSAS data file is an .xls file. For each sampling period, the file records the channels listed below. Sampling periods are listed in rows, while data channels are listed in columns. -
Page 56: Appendix B: Revisions To Manual
Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS) Appendix B: Revisions to Manual Rev. Date Rev No. Summary Section 10-2-09 Reformatted sections and figures; inserted title page, TOC, and legal disclaimer 10-14-09 Omitted BOM and Schematics Appendix Appendixes Changed/reformatted headings in calibration section...
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