Instruments

A type of fishing methodology sometimes used to collect fish census data. It is a hook at the end of a line.

The Hydrothermal Organic Geochemistry (HOG) sampler is designed to collect large volume (2–9 L) fluid samples with minimal introduction of organic or microbial contamination, and to be powered and deployed in real time from a submersible. Additional design constraints include utilizing materials appropriate for sampling fluids with elevated temperatures, fitting the sampler into the space available on the submersible, and minimizing the time needed to remove samples and prepare the sampler for re-deployment between dives. 

The HOBO U20L is designed for monitoring changing water levels in a variety of applications including tidal areas, streams, lakes, wetlands, and groundwater. It outputs pressure, water level, and temperature data. The instrument can record samples, sensor measurements at each logging interval, and events data, occurrences such as a bad battery or host connected. The samples are recorded as absolute pressure values, which are later converted to water level readings using software. Absolute pressure is atmospheric pressure plus water head. The deployment of an additional HOBO U20L at the surface can be used to compensate for barometric pressure changes. Each instrument is individually calibrated. They require a coupler and optic base station or HOBO waterproof shuttle to connect to a computer. The instrument is operated with a 3.6 V lithium battery.

This series contains 3 models, U20L-01, U20L-02, and U20L-04, with different operation ranges, calibrated ranges, and burst pressures. The pressure sensor is temperature compensated between 0 and 40 degrees Celsius (C), and calibrated between 69 and a maximum of 400 kPa (depending on the model). Its accuracy is within 0.3 % of the full scale for absolute pressure, and 0.1 % FS for water level readings. The temperature sensor operates between -20 and 50 degrees C, with an accuracy of 0.44 deg C, and a resolution of 0.1 deg C. The drift is 0.1 deg C per year.

Membrane desolvation module that reduces solvent derived polyatomic interferences in the ICPMS mass spectrum. Both aqueous and organic solutions can be desolvated.

The Hensen Net was invented by Christian Andreas Victor Hensen (February 10, 1835 - April 5, 1924) who was a German researcher considered by many to be the 'father' of Biological Oceanography. Hensen is credited with first using the term 'plankton', and the Hensen Net is one of several sampling devices he invented to help with sample collection. The Hensen Net has a 'reducing cone' forward of the net mouth, a simple closure system and a cod end collection device.

References:
Hensen, V., 1887. Uber die Bestimmung des Planktons oder des im Meere treibenden Materials an Pflanzen und Thieren. Berichte der Kommssion wissenschaftlichen Untersuchung der deutschen Meere in Kiel 5, pp. 1-107.

Hensen, V., 1895. Methodik der untersuchungen. Ergebnisse der Plankton-Expedition der Humbolt-Stiftung, Lipsius and Tischer, Kiel.

Handline fishing, or handlining, is a fishing technique where a single fishing line is held in the hands. A handline is a relatively large diameter line that can be pulled by hand, and it has a jig attached at the end. Handlines are frequently used for catching fish or squid that are schooling near the surface, thus a long haul by hand is not necessary.

A hand net (also called a scoop net or dip net) is a net or mesh basket held open by a hoop. They are used for scooping fish near the surface of the water.

Compass with a motorized gyroscope that tracks true north (heading).

The Greene Bomber is a ENDECO V-fin towed body with overall dimensions of length: 139.7 cm; width at front: 66 cm; width at rear: 142.2 cm; height: 48.26 cm. It is constructed primarily of fiberglass. Since the early 1990's it has been towed just below the sea surface with acoustic and environmental sensors to provide continuous profiles of the water column acoustic backscattering and target strengths from zooplankton with a size range of ~ 1.5 mm to 100 mm, and sea surface environmental properties (temperature, salinity, and fluorescence). It was first used with a BioSonics dual-beam acoustic system operating at 420 kHz and 1 MHz or 120 and 420 kHz. The environmental sensing system (ESS) was the ESS used on MOCNESS. In 1997 the acoustics were changed to a HTI acousitic system with 120 and 420 kHz transducers. In 2010, two additional HTI transducers (43 and 200 kHz) were added. For additional detail see:

Wiebe, P. and C. Greene. 1994. The use of high frequency acoustics in the study of zooplankton spatial and temporal patterns. Proc. NIPR Symp. Polar Biol. 7: 133-157.

Wiebe, P.H., D. Mountain, T.K. Stanton, C. Greene, G. Lough, S. Kaartvedt, J. Dawson, and N. Copley. 1996. Acoustical study of the spatial distribution of plankton on Georges Bank and the relation of volume backscattering strength to the taxonomic composition of the plankton. Deep-Sea Research II. 43: 1971-2001.

Wiebe, PH; Stanton, T K; Benfield, M C; Mountain, D G; Greene, CH. 1997. High-frequency acoustic volume backscattering in the Georges Bank coastal region and its interpretation using scattering models. IEEE Journal of Oceanic Engineering22(3): 445-464.

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis. The U.S. Air Force develops, maintains, and operates the space and control segments of the NAVSTAR GPS transmitter system. Ships use a variety of receivers (e.g. Trimble and Ashtech) to interpret the GPS signal and determine accurate latitude and longitude.

Instruments that separate components in aqueous or organic solution based on molecular size generally for molecular weight determination. Gel permeation chromatography (GPC) is a type of size exclusion chromatography (SEC), that separates analytes on the basis of size.

GO-FLO bottle cast used to collect water samples for pigment, nutrient, plankton, etc. The GO-FLO sampling bottle is specially designed to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths.

Integrated Ocean Drilling Program borehole CORK (Circulation Obviation Retrofit Kit) observatories provide long-term access to hydrothermal fluids circulating within the basaltic crust (basement), providing invaluable opportunities to study the deep biosphere. We describe the design and application parameters of the GeoMICROBE instrumented sled, an autonomous sensor and fluid sampling system. The GeoMICROBE system couples with CORK fluid delivery lines to draw large volumes of fluids from crustal aquifers to the seafloor. These fluids pass a series of in-line sensors and an in situ filtration and collection system. GeoMICROBE’s major components include a primary valve manifold system, a positive displacement primary pump, sensors (e.g., fluid flow rate, temperature, dissolved O2, electrochemistry-voltammetry analyzer), a 48-port in situ filtration and fluid collection system, computerized controller, seven 24 V-40 A batteries and wet-mateable (ODI) communications with submersibles. This constantly evolving system has been successfully connected to IODP Hole 1301A on the eastern flank of the Juan de Fuca Ridge. 

Reference: Cowen, J.P., Copson, D., Jolly, J., Hsieh, C.-C., Matsumoto, R., Glazer, B.T. et al. (2012) Advanced instrument system for real-time and time-series microbial geochemical sampling of the deep (basaltic) crustal biosphere., Deep-Sea Research I, 61: 43-56 doi:10.1016/j.dsr.2011.11.004

An on-line gas preparation and introduction system for isotope ratio mass spectrometry that is designed for high precision isotope and molecular ratio determination of headspace samples, including water equilibration, carbonates and atmospheric gases. The instrument allows for the use of a dual viscous flow inlet system of repetitive measurements of sample and standard gas on a continuous flow isotope ratio mass spectrometer (CF-IRMS) system. The sample volume is the sample vial (instead of a metal bellows), and the reference gas volume is a pressurized gas tank. The instrument consists of a user programmable autosampler, a gas sampling system, a maintenance-free water removal system, a loop injection system, an isothermal gas chromatograph (GC), an active open split interface, a reference gas injection system with three reference ports, and one or two optional LN2 traps for cryofocusing. The gas sampling system includes a two port needle which adds a gentle flow of He into the sample vial, diluting and displacing sample gas. Water is removed from the sample gas through diffusion traps. The loop injector aliquots the sample gas onto the GC column, which separates the molecular species. The reference gas injection system allows accurate referencing of each sample aliquot to isotopic standards. The system can be used with several options including a carbonate reaction kit that allows injection of anhydrous phospohric acid into sample vials.

Gas Analyzers - Instruments for determining the qualitative and quantitative composition of gas mixtures.

In Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, the mass-to-charge ratio (m/z) of an ion is experimentally determined by measuring the frequency at which the ion processes in a magnetic field. These frequencies, which are typically in the 100 KHz to MHz regime, can be measured with modern electronics making it possible to determine the mass of an ion to within +/- 0.000005 amu or 5 ppm.

A lyophilizer, also known as freeze dryer or liofilizador, is a device that is used to freeze-dry material.

A Folsom Plankton Splitter is used for sub-sampling of plankton and ichthyoplankton samples.

Imaging cytometers are automated instruments that quantify properties of single cells, one cell at a time. They combine some aspects of flow cytometry with particle imaging capabilities in an automated device to classify small particles, including phytoplankton and protozoa. They can measure a variety of properties: cell size, cell granularity, cell aspect ratio, equivalent spherical diameter (ESD) and area-based diameter (ABD) [to estimate bio-volume, which is used to estimate cell carbon biomass]. Particle images are digitally recorded and sorted into different classes according to training libraries using a support vector machine (supervised learning methods). The instruments particle-size is calibrated using different sizes of latex beads.

The FlowCam VS series are automated imaging-in-flow instruments that generate high-resolution digital images for measuring size and shape of microscopic particles. The sample introduced in the system is attracted by a peristaltic or a syringe pump into a flow cell (or flow chamber) with known dimensions, located in front of a microscope objective which is connected to a camera video. The benchtop model is ideally suited to a typical laboratory environment with applications in oceanographic research, municipal water, biopharmaceutical formulations, chemicals, oil and gas, biofuels, and many other markets. FlowCam VS is available in four models, from the imaging-only VS-I (i.e. without excitation wavelength or fluorescence emission wavelengths) to the top-of-the-line VS-IV with two channels of fluorescence measurement and scatter triggering capabilities. The instrument can measure particles between 2µm and 2mm; can analyse in vivo or fixed samples; has a flow rate between 0.005 ml/minute and 250 ml/minute (dependant upon magnification, flow cell depth, camera frame rate, efficiency desired, etc.). It can produce either 8-bit Grayscale (Monochrome Camera) or 24-bit Colour (Colour Camera) images, depending on the model.

Flow cytometers (FC or FCM) are automated instruments that quantitate properties of single cells, one cell at a time. They can measure cell size, cell granularity, the amounts of cell components such as total DNA, newly synthesized DNA, gene expression as the amount messenger RNA for a particular gene, amounts of specific surface receptors, amounts of intracellular proteins, or transient signalling events in living cells.
(from: http://www.bio.umass.edu/micro/immunology/facs542/facswhat.htm)

Pound nets are passive, stationary gear used for live entrapment of fish species. The gear is composed of fiber netting. Floating pound nets use floating toggles and buoys at the surface and are held taught below the surface using anchors.


A pound net consists of: (1) a net body or crib where the entrapment takes place, (2) a least one mesh heart that helps funnel fish into the crib, and (3) a straight leader or hedging which leads fish toward the crib. Fish swimming along the shore are turned toward the crib by the hedging, guided into the heart, and into the crib where they are removed.



(Description from Maryland Dept of Natural Resources)

Used to catch fish.

A flame ionization detector (FID) is a scientific instrument that measures the concentration of organic species in a gas stream. It is frequently used as a detector in gas chromatography. Standalone FIDs can also be used in applications such as landfill gas monitoring, fugitive emissions monitoring and internal combustion engine emissions measurement in stationary or portable instruments.

An instrument that performs flow injection analysis. Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream. FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques.

The MBARI Environmental Sample Processor—the ESP—provides on-site (in situ) collection and analysis of water samples from the subsurface ocean. The instrument is an electromechanical/fluidic system designed to collect discrete water samples, concentrate microorganisms or particles, and automate application of molecular probes and qPCR which identify microorganisms and their gene products. The ESP also archives samples so that further analyses may be done after the instrument is recovered.

Environmental Sample Processor

See references below for methodology used on the ESP:
Greenfield, D.I., R. Marin III, S. Jensen, E. Massion, B. Roman, J. Feldman, C. Scholin (2006). Application of the Environmental Sample Processor (ESP) methodology for quantifying Pseudo-nitzschia australis using ribosomal RNA-targeted probes in sandwich and fluorescent in situ hybridization.  Limnology and Oceanography: Methods 4: 426-435.

Greenfield, D., R. Marin III, G.J. Doucette, C. Mikulski, S. Jensen, B. Roman, N. Alvarado, and C.A. Scholin (2008).  Field applications of the second-generation Environmental Sample Processor (ESP) for remote detection of harmful algae: 2006-2007.  Limnology and Oceanography: Methods 6: 667-679.

Marin III, R., and C. Scholin (2010). Sandwich Hybridization.  In: Microscopic and molecular methods for quantitative phytoplankton analysis (Chapter 12), edited by B. Karlson, C. Cusack, and E. Bresnan, E.. IOC Manuals and Guides, no. 55. (IOC/2010/MG/55)  Paris, UNESCO. 110 pp.

Ottesen, E.A., R. Marin III, C.M. Preston, C.R. Young, J.P. Ryan, C.A. Scholin, and E.F. DeLong (2011). Metatranscriptomic analysis of autonomously collected and preserved marine bacterioplankton. The ISME Journal, 5: 1881-1895, doi: 10.1038/ismej.2011.70.

Ottesen, E.A., C.R. Young, J.M. Eppley, J.P. Ryan, F.P. Chavez, C.A. Scholin, and E.F. DeLong (2013). Pattern and synchrony of gene expression among sympatric marine microbial populations. Proceedings of the National Academy of Sciences, 110: E488-E497, doi: 10.1073/pnas.1222099110.

Ottesen, E.A., C.M. Young, S.M. Gifford, J.M. Eppley, R. Marin III, S.C. Schuster, C.A. Scholin, and E.F. DeLong (2014). Multispecies diel transcriptional oscillations in open ocean heterotrophic bacterial assemblages. Science, 345: 207-212, 10.1126/science.1252476.

Preston, C.M., A. Harris, J.P. Ryan, B. Roman, R. Marin III, S. Jensen, C. Everlove, J. Birch, J.M. Dzenitis, D. Pargett, M. Adachi, K. Turk, J.P. Zehr, and C.A. Scholin (2011). Underwater application of quantitative PCR on an ocean mooring. PLoS ONE, 6:e22522, doi: 10.1371/journal.pone.0022522.

Robidart, J.C., C.M. Preston, R.W. Paerl, K.A. Turk, A.C. Mosier, C.A. Francis, C.A. Scholin, and J.P. Zehr (2011). Seasonal Synechococcus and Thaumarchaeal population dynamics examined with high resolution with remote in situ instrumentation. The ISME Journal, 6: 513-523, doi: 10.1038/ismej.2011.127.

Robidart, J., M.J. Church, J.P. Ryan, F. Ascani, S.T. Wilson, D. Bombar, R. Marin III, K.J. Richards, D.M. Karl, C.A. Scholin, and J.P Zehr (2014). Ecogenomic sensor reveals controls on N2-fixing microorganisms in the North Pacific Ocean. The ISME Journal, 8: 1175-1185, 10.1038/ismej.2013.244.

Saito, M.A., V.V. Bulygin, D.M. Moran, C. Taylor, and C. Scholin (2011). Examination of microbial proteome preservation techniques applicable to autonomous environmental sample collection. Frontiers in Aquatic Microbiology, 2: doi: 10.3389/fmicb.2011.00215.

Scholin, C.. (2010).  What are “ecogenomic sensors?” A review and thoughts for the future. Ocean Science 6: 51-60.

Ussler III, W., C.M. Preston, P. Tavormina, D. Pargett, S. Jensen, B. Roman, R. Marin III, S.R. Shah, P.R. Girguis, J.M. Birch, V.J. Orphan, and C. Scholin (2013). Autonomous application of quantitative PCR in the deep sea: In situ surveys of aerobic methanotrophs using the deep-sea Environmental Sample Processor. Environmental Science and Technology, 47: 9339–9346, doi: 10.1021/es4023199.

Varaljay, V.A, J. Robidart, C.M. Preston, S.M. Gifford, B. Durham, A.S. Burns, J.P. Ryan, R. Marin III, R.P. Kiene, J.P Zehr, C.A. Scholin, M. Moran. 2015. Single-taxon field measurements of bacterial gene regulation controlling DMSP fate. ISME Journal, doi:10.1038/ismej.2015.23|

This radiometer measures sun and sky irradiance in the range of wavelengths 0.285 to 2.8 microns, including most of the solar spectrum. The PSP is intended to weight the energy flux in all wavelengths equally. It is a "hemispheric receiver" intended to approximate the
cosine response for oblique rays. The Eppley Precision Spectral Pyranometer (PSP) is primarily used where high accuracy is required or where it is used to calibrate other pyranometers. The PSP outputs a low level voltage ranging from 0 to a maximum of about 12mV depending on sensor calibration and radiation level. An instruction manual provided by Eppley contains the sensor calibration constant and serial number. The Precision Spectral Pyranometer is a World Meteorological Organization First Class Radiometer and comes with a calibration certificate traceable to the World Radiation Reference and a temperature compensation curve. More information is available from Eppley Labs.

A high-resolution (HR) inductively coupled plasma (ICP) mass spectrometer (MS) composed of a dual mode secondary electron multiplier (SEM) and a Faraday detector. The ELEMENT XR instrument has a dynamic range of 5 x 10^7 to 1 x 10^12 counts per second (cps), and allows simultaneous measurement of elements at concentrations over 1000 ug/g.

An electronic jig machine is used to mechanically jig a fish hook or lure with a bait casting reel without using the fishing rod to jig the lure. Normally to jig a fish hook or lure one must move the fishing rod either vertically, horizontally, or jerk the fishing line by hand. The jigging action of this bait cast reel (how rapid and how long in distance the jig will travel) will determine the desired intensity and resonance of the rattle used in the lure to attract or snag the fish. With very simple controls, the equipment functions automatically since it is programmed to suit the actual fishing area, the fishing method and the type of fish.

The ECO BB measures scattering at 117 degrees, the angle determined as a minimum convergence point for variations in the volume scattering function (VSF) induced by suspended materials and water itself. As a result, the signal measured by this meter is less determined by the type and size of the materials in the water and is more directly correlated to the concentration of the materials. Conversely, the meter provides unparalleled accuracy for any single-angle measurement in determining the optical backscattering coefficient: an important parameter for remote sensing and in many in-water bio-optical applications.

A single-beam echo sounder is an instrument that measures water depth at a single point below the platform by timing pulses of sound reflected on the seafloor. The echo sounder transmits and receives sound, accurately measuring the time it takes to leave the sounder, reach the bottom and return to the sounder. It then converts this information into digital or graphic representations of the bottom depth and relief.
The average echo sounder consists of a transmission and reception unit that sends sound signals through the water, receives and decodes information and converts that information into either a graphic or visual form. Attached to the receiver is a transducer that acts as a microphone and a speaker under the water. Sound waves travel at approximately 1500 m/s through the water dependent on water temperature". more from LMS Technologies

A core drill is a drill specifically designed to remove a cylinder of material, much like a hole saw. The material left inside the drill bit is referred to as the core.

Core drills are used frequently in mineral exploration where the coring may be several hundred to several thousand feet in length. The core samples are recovered and examined by geologists for mineral percentages and stratigraphic contact points. This gives exploration companies the information necessary to begin or abandon mining operations in a particular area.

The remotely operated vehicle (ROV) Doc Ricketts is operated by the Monterey Bay Aquarium Research Institute (MBARI). ROV Doc Ricketts is capable of diving to 4000 meters (about 2.5 miles). The R/V Western Flyer is the support vessel for Doc Ricketts and was designed with a center well whose floor can be opened to allow Doc Ricketts to be launched from within the ship into the water below. For a complete description, see: https://www.mbari.org/at-sea/vehicles/remotely-operated-vehicles/rov-doc-ricketts/

An electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed

A Digital Inline Holographic Microscope (DIHM) uses coherent (laser) light and a digital camera to image objects with micrometer scale resolution. A portion of the light scattered by illuminated objects interferes with incident light in a predictable manner. The resulting interference patterns projected onto a two-dimensional plane (i.e. digital camera sensor) are recorded as holograms. These digital holograms are then numerically reconstructed to produce an in-focus image at a given distance from the recording plane. A relatively large illuminated volume (>100 mL) can be reconstructed in this manner to produce a single image with an extended depth of field. 

Portable or bench-top instruments to measure density of liquids. [lab]

The Daly detector was designed by N.R Daly in the 1960’s. The design uses a conversion dynode to convert incident ions into electrons. It also separates the multiplication electronics away from the ion beam preventing secondary ion production on the multiplication dynodes.

The CytoSense is a portable, benchtop autonomous flow cytometer designed for phytoplankton species classification and analysis of filamentous algae. It can also be used in situ to reveal temporal and spatial phytoplankton variability. It can be remotely controlled, and has been specifically designed to record the optical pulse shapes of suspended particles between <1 and 800 micrometres in diameter and up to 4 millimetres in length (for chain-forming cells recording) in relatively large volumes of water (several centimetres cubed per sample). The instrument combines high sensitivity with an extremely wide particle size range (from sub-micron up to 1.5 millimetres in diameter) and acquires multiple data points per particle, which distinguishes the CytoSense from conventional flow cytometers. The CytoSense has a modular design, with various upgrades and accessories available to suit user requirements. These include additional lasers, optional cameras to take pictures of particles and a widened flow cell. The sample intake speed ranges from 0.07 - 17 microlitres per second, allowing high particle loads (thousands of particles per second) as well as very low concentrations.

Alternate name: CytoBuoy CytoSense flow cytometer

A net towed through the water column designed to sample free-swimming nekton or fish, varies in design depending on the research project.

A CTD-fluorometer is an instrument package designed to measure hydrographic information (pressure, temperature and conductivity) and chlorophyll fluorescence.

CTD measurements taken during a SeaSoar tow.

Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics, no specific unit identified. This instrument designation is used when specific make and model are not known. See also other SeaBird instruments listed under CTD. More information from Sea-Bird Electronics.

The Sea-Bird SBE 911 is a type of CTD instrument package. The SBE 911 includes the SBE 9 Underwater Unit and the SBE 11 Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 and SBE 11 is called a SBE 911. The SBE 9 uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 and SBE 4). The SBE 9 CTD can be configured with auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). More information from Sea-Bird Electronics.

The Sea-Bird SBE 41 CTD module was originally developed in 1997 for integration with sub-surface oceanographic floats. It uses MicroCAT Temperature, Conductivity, and Pressure sensors.

The Sea-Bird SBE 19 SEACAT Recorder measures conductivity, temperature, and pressure (depth). The SEACAT is self-powered and self-contained and can be deployed in profiling or moored mode. The SBE 19 SEACAT was replaced in 2001 by the 19plus. more information from Sea-Bird Electronics

This is an integrated instrument package comprising a Neil Brown Instrument Systems Mark III Conductivity, Temperature, Depth (CTD) profiler unit with a Tracor Acoustic Profiling System (TAPS). (see TAPS entry for a description of that instrument)

The CTD part of the MOCNESS includes 1) a pressure (depth) sensor which is a thermally isolated titanium strain gauge with a standard range of 0-5000 decibars full scale, 2) A Sea Bird temperature sensor whose frequency output is measured and sent to the surface for logging and conversion to temperature by the software in the MOCNESS computer (The system allows better than 1 milli-degree resolution at 10 Hz sampling rate), and 3) A Sea Bird conductivity sensor whose output frequency is measured and sent to the surface for logging and conversion to conductivity by the software in the computer (The system allows better than 1 micro mho/cm at 10 Hz sampling rate). The data rate depends on the speed of the computer and the quality of the cable. With a good cable, the system can operate at 2400 baud, sampling all variables at 2 times per second. One sample every 4 seconds is the default, although the hardware can operate much faster. (From The MOCNESS Manual)

CTD measurements taken by the Falmouth Scientific Instruments sensor.

A CT scan makes use of computer-processed combinations of many X-ray measurements taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of specific areas of a scanned object.

Measures the total condensation nucleus concentration of aerosol particles.