Instruments

An automated acid-base titrator for use in aquatic carbon dioxide parameter analysis. The titrator provides standardisation and sample analysis, using the Gran titration procedure for alkalinity determination of seawater and brackish waters. It is designed for both shipboard and land based laboratory use. The precision of the instrument is 0.1 percent or higher, and sample volumes may range from 10-25 ml. Titration takes approximately 8 minutes per sample, and the repeatability is within plus or minus 1-2 micromoles per kg.

A family of self-contained Doppler current profilers, Nortek Aquadopp Profilers are often referred to as AquaPro instruments. They are designed for deployment on the seabed, moorings, buoys or fixed structures. They can feature a range of transducers - 400 kHz (60-90m range: 2-8m cell size), 600 kHz (30-40m range: 1-4m cell size), Z-cell 600 kHz, 1 MHz (12-25m range: 0.3-4m cell size), Z-cell 1MHz, 2 MHz (4-10m range:0.1-2m cell size) and side-looking. Each transducer has 3 beams and the instrument has a maximum of 128 cells. Current speeds up to 10 m/s may be measured at an accuracy of 1% of measured value ±0.5cm/s. The standard depth rating is 300 m with 3000 m or 600m versions available. Temperature (embedded thermistor with 0.1C accuracy and 0.01C resolution), compass (magnetometer with 2 degrees accuracy and 0.1 degree resolution providing tilt <20 degrees), tilt (liquid level with 0.2 degree accuracy and 0.1 degree resolution) and pressure (piezo resistive with accuracy of 0.5% full scale - usually 100m - and resolution of 0.005% full scale) sensors are provided as standard.

Immersible or in-line liquid cooling device, usually with temperature control.

Accelerated solvent extraction (ASE) is a method for extracting various chemicals from a complex solid or semisolid sample matrix. The process uses high temperature and pressure, which results in the extraction taking less time and requiring less solvent, and possibly also giving better analyte recovery, than traditional methods that use less extreme conditions.

Atmospheric Sampling Mast - used to collect airborne samples for analysis such as in aerosol studies.

Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached.

The autonomous underwater vehicle (AUV) Sentry is a fully autonomous underwater vehicle capable of exploring the ocean down to 6,000 meters (19,685 feet) depth. Sentry builds on the success of its predecessor the ABE, with improved speed, range, and maneuverability.

Sentry's hydrodynamic shape also allows faster ascents and descents. Sentry carries a superior science sensor suite and an increased science payload enabling it to be used for both mid-water and near-seabed oceanographic investigations. Sentry produces bathymetric, sidescan, subbottom, and magnetic maps of the seafloor and is capable of taking digital bottom photographs in a variety of deep-sea terrains such as mid-ocean ridges, deep-sea vents, and cold seeps at ocean margins. Sentry is uniquely able to operate in extreme terrain, including volcano caldera and scarps. Sentry's navigation system uses a doppler velocity log and inertial navigation system, aided by acoustic navigation systems (USBL or LBL). The USBL system also provides acoustic communications, which can be used to obtain the vehicle state and sensor status as well as to retask the vehicle while on the bottom. In addition its standard sensors, Sentry has carried a variety of science-supplied sensors, including the Nakamura redox potential probe, ACFR 3-D imaging system, and the Tethys in-situ mass spectrometer.

Sentry can be used to locate and quantify hydrothermal fluxes. Sentry is also capable of a much wider range of oceanographic applications due to its superior sensing suite, increased speed and endurance, improved navigation, and acoustic communications. Sentry can be used as a stand alone vehicle or in tandem with Alvin or an ROV to increase the efficiency of deep-submergence investigations.

More information is available from the operator site at URL: http://www.whoi.edu/main/sentry

A family of instruments that simultaneously measure current profiles and wave height and direction designed for coastal monitoring.

An aXBT is an Expendable Bathythermograph (XBT) designed to be launched from an aircraft (often a P3 type aircraft) as opposed to a ship. The aXBT collects data in a similar fashion to an XBT, and once the probe hit the sea surface, it free falls through the water column.

Bioanalytical Systems (BASi) Mercury drop electrodes are generated by the BASi Controlled Growth Mercury Electrode (CGME) in three modes:

DME (Dropping Mercury Electrode) - mercury is allowed to flow freely from the reservoir down the capillary and so the growth of the mercury drop and its lifetime is controlled by gravity. (The optional 100 um capillary is recommended for this mode.)

SMDE (Static Mercury Drop Electrode) - the drop size is determined by the length of time for which the fast-response capillary valve is opened, and the drop is dislodged by a drop knocker. The dispense/knock timing is microprocessor-controlled and is typically coordinated with the potential pulse or square-wave waveform. This mode can also used to generate the Hanging Mercury Drop Electrode required for stripping experiments.

CGME (Controlled Growth Mercury Electrode) - the mercury drop is grown by a series of pulses that open the capillary valve. The number of pulses, their duration, and their frequency can be varied by PC control, providing great flexibility in both the drop size and its rate of growth. This CGME mode can be used for both polarographic and stripping experiments.

http://www.basinc.com/products/ec/cgme.php

The FACSCalibur flow cytometer is an autonomous benchtop flow cytometer designed for routine cell analysis, assay development, verification and identification of cellular populations. It is equipped with a blue (488 nm) air-cooled argon laser and a red (635 nm) diode laser. For each particle (cell), five optical parameters can be recorded from the 488 nm laser beam excitation: two light scatter signals, namely forward and right angle, and three fluorescences corresponding to emissions in green (530/30 nm BP), orange (585/42 nm BP) and red (670 nm LP) wavelength ranges. A far red fluorescence (661/16 nm BP) induced by the red diode can also be recorded. Data are analysed using BD Biosciences CellQuest software. Optional features include a cell sorting option, allowing users to identify and isolate a population of interest and a HTS option (High-throughput (HT) or Standard (STD) mode), where sample volumes range from 2-10 microlitres in HT mode and 2-200 microlitres in STD mode. An optional BD FACS Loader tube-lifter can be used to verify tube position and rack identification. The instrument has a capture rate of 300 cells per second, supports 40 (12 x 75 mm) tubes per rack, and has an operating temperature ranging from 16-29 degC.

An instrument consisting of an electronic voltmeter and pH-responsive electrode that gives a direct conversion of voltage differences to differences of pH at the measurement temperature. (McGraw-Hill Dictionary of Scientific and Technical Terms)

This instrument does not map to the NERC instrument vocabulary term for 'pH Sensor' which measures values in the water column. Benchtop models are typically employed for stationary lab applications.

Handheld binoculars, generally used for bird or mammal observations.

BIOMAPER II is a set of sensors on a long aluminum frame that resembles the tail of a World War II airplane. A research vessel tows the instrument through the water on a specialized tow cable that sends power to the sensors and brings data back to the ship. People use BIOMAPER II to learn about phytoplankton and zooplankton over areas that are too large to study with the traditional net-and-microscope method. Whereas nets can sample areas up to about 5 meters (16 feet) on a side, BIOMAPER II can record data from 500 meters (1,640 feet) or more of the water column at a time. The instrument's standard suite of sensors were chosen for studying plankton: a five-frequency sonar system, a video plankton recorder and an environmental sensor system (ESS, like the one on MOCNESS). The ESS measures water temperature, salinity, oxygen, chlorophyll and light levels. BIOMAPER II also has room for attaching other instruments for specific uses. The instrument's official name is BIOMAPER-II: the BIo-Optical Multi-frequency Acoustical and Physical Environmental Recorder. The Roman numeral II indicates that it's a redesign of the original BIOMAPER, a prototype that was invented and tested in the mid 1990s. (more information).

An automated DNA size selection instrument, with pulsed-field electrophoresis for resolving and collecting high molecular weight DNA. The instrument is used to automatically extract DNA fragments of a user selected size for downstream technologies such as miRNA isolation, DNA sequencing, RNA-seq, genotyping, DNA sequencing, ChIP-seq, and Long-read sequencing. The instrument uses electrophoresis along with laser detection or other imaging technology to determine when to start collecting DNA based on size ranges entered by the user. Once the DNA is no longer in the desired size range, collection ceases. The instrument has electrophoresis voltage options: 25V, 100V or 150V constant, or 100V pulsed field. The optical detection wavelength is 470 nm excitation, and 525 nm emission. The instrument can run up to 5 samples/gel cassettes at a time, with no possibility of cross contamination.

Bio-Optical Profiling System (BOPS) is an updated version of the BOPS originally developed by Smith et al. (1984) and is used to collect optical data. The heart of the BOPS is a Biospherical instruments MER-1048 Spectroradiometer which measures up and downwelling spectral irradiance and upwelling spectral radiance. The MER-1048 also has sensors for Photosynthetically Available Radiation (PAR), depth, tilt and roll. In addition, temperature and conductivity are measured with a Sea-Bird CTD, chlorophyll fluorescence is measured with a Sea Tech fluorometer and beam transmission with a Sea Tech 25-cm transmissometer. The Mer-1048 acquires all the data 16 times a second, averages it to four records a second and sends it up the cable to a deck box and a Compaq-286 computer which stores the data on the hard disk. Additionally, a deck cell measures the downwelling surface irradiance in four spectral channels. Also surface PAR is measured continuously using a Biospherical Instruments QSR-240 Integrating PAR sensor. The profile data is commonly filtered to remove obvious data spikes and then binned into one-meter averages.

Raymond C. Smith, Charles R. Booth, and Jeffrey L. Star, "Oceanographic biooptical profiling system," Appl. Opt. 23, 2791-2797 (1984).

General description of a box corer:

A box corer is a marine geological tool that recovers undisturbed soft surface sediments. It is designed for minimum disturbance of the sediment surface by bow wave effects. Traditionally, it consists of a weighted stem fitted to a square sampling box. The corer is lowered vertically until it impacts with the seabed. At this point the instrument is triggered by a trip as the main coring stem passes through its frame. While pulling the corer out of the sediment a spade swings underneath the sample to prevent loss. When hauled back on board, the spade is under the box. (definition from the SeaVox Device Catalog)

Box corers are one of the simplest and most commonly used types of sediment corers. The stainless steel sampling box can contain a surface sediment block as large as 50cm x 50cm x 75cm with negligible disturbance. Once the sediment is recovered onboard, the sediment box can be detached from the frame and taken to a laboratory for subsampling and further analysis. The core sample size is controlled by the speed at which the corer is lowered into the ocean bottom. When the bottom is firm, a higher speed is required to obtain a complete sample. A depth pinger or other depth indicator is generally used to determine when the box is completely filled with sediment. Once the core box is filled with sediment, the sample is secured by moving the spade-closing lever arm to lower the cutting edge of the spade into the sediment, until the spade completely covers the bottom of the sediment box. (definition from Woods Hole Oceanographic Institution).

These samplers are designed to collect an accurate representative sample of the sediment bottom. The bite of the sampler should be deep enough so all depths are sampled equally. The closing mechanism is required to completely close and hold the sample as well as prevent wash-out during retrieval. Likewise, during descent the sampler should be designed to minimize disturbance of the topmost sediment by the pressure wave as it is lowered to the bottom.

The California Cooperative Oceanic Fisheries Investigations (CalCOFI) Vertical Egg Tow device is a type of vertical net tow. Note that mesh sizes may vary.

A laboratory instrument that simultaneously determines total nitrogen, total hydrogen, and total carbon in a solid sample. The sample is completely and instantaneously oxidized by flash combustion, which converts all organic and inorganic substances into combustion products. The resulting combustion gases pass through a reduction furnace and are swept into the chromatographic column by the helium carrier gas. The gases are separated in the column and quantified or they can be introduced into another instrument, such as an isotope ratio mass spectrometer, for further analysis. The instrument was originally manufactured by CE instruments (formerly Carlo Erba) and has since been replaced by Thermo Scientific (part of Thermo Fisher Scientific). This model is no longer in production.

A Cary 50 spectrophotometer measures absorbance (200-800 nm).

The Sontek CastAway-CTD (manufactured by Xylem) is a handheld castable instrument that provides instantaneous profiles of temperature, salinity, and sound speed. Each cast is referenced with both time and location using its built-in GPS receiver. The CastAway software displays profiles of the casts in addition to mapping the locations of the data collection points. The CastAway-CTD has a 5 Hz response and sampling rate, accurate to 0.1 (PSS-78), 0.05° Celsius.

Conductivity range is 0 to 100,000 µS/cm.
Temperature range is -5° to 45° Celsius.
Pressure range is 0 to 100 decibars.

Further specs and information can be found on the manufacturer's website: https://www.xylem.com/en-us/brands/wtw/wtw-products/castaway-ctd/

Instruments that illuminate a sample inside an optical cavity, typically using laser light, and measure the concentration or amount of a species in gas phase by absorption spectroscopy. Techniques include cavity ring-down spectroscopy (CRDS) and integrated cavity output spectroscopy (ICOS).

The Carbon Flux Explorer (CFE) is designed to perform sustained high-frequency observations of POC and PIC sedimentation within the upper kilometer (or twilight zone) of the ocean for seasons to years and to operate in an observational context not dependent on ships. The CFE melds the concept of current-following, sample-collecting neutrally buoyant sediment traps with photographic imaging of the particles as they are deposited in a sediment trap.

The CFE and the operation of its particle flux sensing Optical Sedimentation Recorder (OSR) have been discussed in detail in Bishop et al. (2016). CFE has a design mission capability of 8 months of hourly operations (16 months @ 2 hours) and has been demonstrated by deployments of 40 days; CFE design depth is 1500m and it has been proven to 1000 m. The system has demonstrated operations in high sea states.

Diagram: https://datadocs.bco-dmo.org/docs/302/C-SNOW/data_docs/CFE_CFE-Cal.png

Bishop, J. K. B., Fong, M. B., and Wood, T. J.: Robotic observations of high wintertime carbon export in California coastal waters, Biogeosciences, 13, 3109–3129, https://doi.org/10.5194/bg-13-3109-2016, 2016.

Bourne, H. L., Bishop, J. K. B., Wood, T. J., Loew, T. J., and Liu, Y.: Carbon Flux Explorer optical assessment of C, N and P fluxes, Biogeosciences, 16, 1249–1264, https://doi.org/10.5194/bg-16-1249-2019, 2019

A unit that accurately determines the carbon and nitrogen concentrations of organic compounds typically by detecting and measuring their combustion products (CO2 and NO).

"Clarke and Bumpus designed a small two-messenger zooplankton collection system that could be deployed as multiple units on the wire and had a positive means of opening and closing the mouth of the net. A frame attached at the top and bottom to the towing wire supported a cylindrical tube 12.7 cm in diameter and 16 cm long, to which a net was attached. In the mouth of the tube was a flat plate (like a stove pipe damper plate),which closed off the cylinder when the net was deployed. When the first messenger released a spring-loaded latch, the plate was rotated 90 degrees, opening the net; a second messenger rotated it another 90 degrees to close the net. A flowmeter at the back of the cylinder recorded flow through the net." (Wiebe and Benfield, 2003) The instruments were equipped with No. 2 silk nets (22 strands/cm.) and "oblique" hauls were made at a speed of about 2 knots for periods of 25 to 40 minutes.

References:
CLARKE, G. L., AND D. F. BUMPUS, 1940. The Plankton Sampler-an instrument for quantitative plankton investigations. Linnological Society of America, Special Pub., (No. 5): 1-8.

Wiebe, Peter H. and Mark C. Benfield, 2003. From the Hensen net toward four-dimensional biological oceanography. Progress in Oceanography, 56, pp. 7-136.

Measures atmospheric carbon dioxide (CO2) concentration.

Crab pots modified to catch cod. Variously designed: floating v. static; large v. small; two or more large entrances v. one small entrance, rigid v. collapsible.

Conductivity Meter - An electrical conductivity meter (EC meter) measures the electrical conductivity in a solution. Commonly used in hydroponics, aquaculture and freshwater systems to monitor the amount of nutrients, salts or impurities in the water.

The ECS 4010 Nitrogen / Protein Analyzer is an elemental combustion analyser for CHNSO elemental analysis and Nitrogen / Protein determination. The GC oven and separation column have a temperature range of 30-110 degC, with control of +/- 0.1 degC.

The CPR is a plankton sampling instrument designed to be towed from merchant ships or ships of opportunity on their normal sailings. The CPR is towed at a depth of approximately 10 metres. Water passes through the CPR and plankton are filtered onto a slow-moving band of silk (270 micrometre mesh size) and covered by a second silk. The silks and plankton are then spooled into a storage tank containing formalin. On return to the laboratory, the silk is removed from the mechanism and divided into samples representing 10 nautical miles (19 km) of tow.

CPR samples are analyzed in two ways. Firstly, the Phytoplankton Color Index (PCI) is determined for each sample. The colour of the silk is evaluated against a standard colour chart and given a 'green-ness' value based on the visual discoloration of the CPR silk produced by green chlorophyll pigments; the PCI is a semiquantitative estimate of phytoplankton biomass. In this way the PCI takes into account the chloroplasts of broken cells and small phytoplankton which cannot be counted during the microscopic analysis stage. After determination of the PCI, microscopic analysis is undertaken for each sample, and individual phytoplankton and zooplanktontaxa are identified and counted.

Reid, P.C.; Colebrook, J.M.; Matthews, J.B.L.; Aiken, J.; et al. (2003). "The Continuous Plankton Recorder: concepts and history, from plankton indicator to undulating recorders".Progress in Oceanography 58(2-4): 117-175. doi:10.1016/j.pocean.2003.08.002.

Warner, A.J., and Hays, G.C.,; Hays, G (1994). "Sampling by the Continuous Plankton Recorder survey". Progress in Oceanography 34(2–3): 237–256. doi:10.1016/0079-6611(94)90011-6.

The RBR Conductivity, Temperature and Depth instrument:

http://www.rbr-global.com/products/ct-and-ctd-loggers/rbrconcerto-ctd

The Sea-Bird MicroCAT CTD unit is a high-accuracy conductivity and temperature recorder based on the Sea-Bird SBE 37 MicroCAT series of products. It can be configured with optional pressure sensor, internal batteries, memory, built-in Inductive Modem, integral Pump, and/or SBE-43 Integrated Dissolved Oxygen sensor. Constructed of titanium and other non-corroding materials for long life with minimal maintenance, the MicroCAT is designed for long duration on moorings.

In a typical mooring, a modem module housed in the buoy communicates with underwater instruments and is interfaced to a computer or data logger via serial port. The computer or data logger is programmed to poll each instrument on the mooring for its data, and send the data to a telemetry transmitter (satellite link, cell phone, RF modem, etc.). The MicroCAT saves data in memory for upload after recovery, providing a data backup if real-time telemetry is interrupted.

The Neil Brown Instrument Systems Mark III Conductivity, Temperature, Depth (CTD) instrument is an integral unit containing pressure, temperature and conductivity sensors with an optional dissolved oxygen sensor in a pressure-hardened casing. Developed in the 1970s, the Neil Brown CTD unit was able to digitize conductivity, temperature and pressure measurements at sufficient speeds to permit oceanographers to study 10 cm features at winch lowering speeds of 30 meters per minute. The most widely used variant in the 1980s and 1990s was the MK3B. The MK3C fitted with an improved pressure sensor to reduce hysteresis was developed to meet the requirements of the WOCE project. The instrument is no longer in production, but is supported (repair and calibration) by General Oceanics.

The Neil Brown Instrument Systems Mark 5 CTD is used to measure conductivity, temperature, and depth of sea water. The MK5 profiler has a higher sampling rate then the SeaBird SEACAT. (For the GLOBEC Georges Bank project the Mark 5 was instrumented with an expanded suite of sensors and deployed almost exclusively at GLOBEC Standard stations.)

The Sea-Bird SBE 25 SEALOGGER CTD is battery powered and is typically used to record data in memory, eliminating the need for a large vessel, electrical sea cable, and on-board computer. All SBE 25s can also operate in real-time, transmitting data via an opto-isolated RS-232 serial port. Temperature and conductivity are measured by the SBE 3F Temperature sensor and SBE 4 Conductivity sensor (same as those used on the premium SBE 9plus CTD). The SBE 25 also includes the SBE 5P (plastic) or 5T (titanium) Submersible Pump and TC Duct. The pump-controlled, TC-ducted flow configuration significantly reduces salinity spiking caused by ship heave, and in calm waters allows slower descent rates for improved resolution of water column features. Pressure is measured by the modular SBE 29 Temperature Compensated Strain-Gauge Pressure sensor (available in eight depth ranges to suit the operating depth requirement). The SBE 25's modular design makes it easy to configure in the field for a wide range of auxiliary sensors, including optional dissolved oxygen (SBE 43), pH (SBE 18 or SBE 27), fluorescence, transmissivity, PAR, and optical backscatter sensors. More information from Sea-Bird Electronics: http:www.seabird.com.

The Sea-Bird SBE 9 is a type of CTD instrument package. The SBE 9 is the Underwater Unit and is most often combined with the SBE 11 Deck Unit (for real-time readout using conductive wire) when deployed from a research 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, fluorometer, altimeter, etc.). Note that in most cases, it is more accurate to specify SBE 911 than SBE 9 since it is likely a SBE 11 deck unit was used. more information from Sea-Bird Electronics

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

The CTD SEACAT recorder is an instrument package manufactured by Sea-Bird Electronics. The first Sea-Bird SEACAT Recorder was the original SBE 16 SEACAT developed in 1987. There are several model numbers including the SBE 16plus (SEACAT C-T Recorder (P optional))and the SBE 19 (SBE 19plus SEACAT Profiler measures conductivity, temperature, and pressure (depth)). More information from Sea-Bird Electronics.

Sea-bird SBE 9 pumped CTD attached to the Triaxus towed undulating platform. The Triaxus towed undulating vehicle, designed and manufactured by MacArtney, achieves high resolution 3-dimensional surveys of the upper 180m of the water column. The standard sensor package includes a Seabird CTD (with optional secondary C and T sensors), transmissometer, dissolved oxygen, chlorophyll fluorometer, and PAR sensor. In addition to this basic configuration, Triaxus can accommodate up to 9 additional sensor packages / sensors. See http://www.macartney.com/systems/remote-technology/triaxus.

A CTD-FRRf fluorometer is an instrument package designed to measure hydrographic information (pressure, temperature and conductivity) and chlorophyll fluorescence. (see more at URL: http://www.chelsea.co.uk/Instruments%20FASTtracka.htm) For example, a Chelsea FASTtracka CTD (conductivity, temperature, and depth) device can be configured with additional sensors to measure fluorescence and photosynthetically active radiation (PAR) in the water column. Fluorescence data collected by the CTD are subsequently calibrated and corrected to give the average concentration of chlorophyll a in the water column. The Chelsea system can be configured as part of a towed package or in a shipboard pumping system. (see more from Chelsea Instruments, Molesey, Surrey, United Kingdom at URL: http://www.chelsea.co.uk/

A Cold Vapor Atomic Fluorescent Spectrophotometer (CVAFS) is an instrument used for quantitative determination of volatile heavy metals, such as mercury. CVAFS make use of the characteristic of mercury that allows vapor measurement at room temperature. Mercury atoms in an inert carrier gas are excited by a collimated UV light source at a particular wavelength. As the atoms return to their non-excited state they re-radiate their absorbed energy at the same wavelength. The fluorescence may be detected using a photomultiplier tube or UV photodiode.

The Deep Autonomous Profiler (DAP) is described in detail in the following publication:
Muir, L., Roman, C., Casagrande, D., and D'Hondt, S. (2021) The Deep Autonomous Profiler (DAP), a Platform for Hadal Profiling and Water Sample Collection. Journal of Atmospheric and Oceanic Technology, vol. 38, no. 10, pp. 1833–1845, 2021. doi:10.1175/JTECH-D-20-0139.1. URL: https://journals.ametsoc.org/view/journals/atot/38/10/JTECH-D-20-0139.1.xml

To summarize:
DAP is a full-ocean-depth profiler rated to 11 kilometers. It was designed to expand the capabilities of a CTD system to the full ocean depth (11 km) by removing the constraints associated with wire-based operations. Removing the tether allows the vehicle to autonomously profile and sample seawater into the hadal region. Because it only requires the ship for deployment and retrieval, the ship can perform other tasks while the DAP is underway. The only source of communication to the DAP while deployed are the acoustic releases.

The DAP is built around a 24-bottle Sea-Bird SBE 32 rosette for 10- or 12-Liter Niskin bottles. The large aluminum bottle-support rings from the standard rosette were modified to reduce weight and are held by the vehicle's custom frame. Syntactic foam provides buoyancy and drop weights are used for descent.

The DAP stands 3.2 meters tall and has a mass of approximately 1400 kilograms (kg) in air empty and 1700 kg when full of water. The titanium electronics bottle, tested to 960 decibars (dBar) in a pressure facility, was designed to house the embedded Raspberry Pi computer and power circuitry. This computer logs data from the SBE 9plus CTD and SBE 43 oxygen sensor, sends commands to the SBE 32 sampler carousel to trigger the sample bottles, and controls the burnwire release. Power for a nominal 24-hour operating time is provided by a 24-volt, 40-amp-hour oil-filled DeepSea Power and Light SeaBattery.

Using drop weights, the profiler descends at a nominal speed of 60 meters per minute through the water column, collecting CTD data. Upon reaching the bottom, a timer is activated and an onboard algorithm processes the descent profile to set the trigger depths for any sample bottles set with an adaptive criteria. Bottom water samples can also be collected according to any preset delays. The bottom time can vary anywhere from 5 minutes to 18 hours. During the ascent, at a nominal speed of 60 meters per minute, the Niskin bottles are triggered at any preset depths specified in the mission file or at adaptively calculated depths based on downcast data. When the DAP surfaces, a radio beacon, Iridium beacon, strobe, radar reflector, and flag are used for recovery by the ship.

The vehicle can currently hold up to 24 Niskin bottles, and up to four pressure-maintaining sample bottles provided by the Scripps Institution of Oceanography.

The Deep Submersible Incubation Device (Deep-SID) is capable of collecting a 4-liter sample that can then be pushed to 8 subsample chambers that contain a fixative. The Deep-SID was used by Dr. Joan Bernhard to conduct in situ grazing experiments during AT18-14.

The Sound Metrics DIDSON 3000 (Dual-Frequency Identification Sonar) multibeam imaging sonar is an acoustic camera that provides almost video-quality images in turbid or dark water where optical systems are ineffective. DIDSON uses acoustic lenses to focus beams and form an acoustic image on the transducer array. DIDSON forms images differently than an optical camera. DIDSON sends out short acoustic pulses in 48 or 96 acoustic beams. These beams are very narrow in the horizontal dimension (0.3° to 0.8°) and wide in the vertical dimension (14°). The beams are adjacent to each other and together form a field-of-view 29° horizontal and 14° vertical. The Didson 3000 is rated to a depth of 3000 meters. It has both Detection and Identification modes. The max frame rate (window length dependent) is 4-21 frames per second.

Discrete analyzers utilize discrete reaction wells to mix and develop the colorimetric reaction, allowing for a wide variety of assays to be performed from one sample. These instruments are ideal for drinking water, wastewater, soil testing, environmental and university or research applications where multiple assays and high throughput are required.

The Milestone DMA-80 is a mercury analyzer used to determine mercury concentrations in liquid and solid samples. The DMA-80 is based on the principles of sample thermal decomposition, mercury amalgamation, and atomic absorption detection. See more: https://milestonesci.com/direct-mercury-analyzer/

Digital Polymerase Chain Reaction (dPCR)

The PDCR 4000 Series provides a complete range of mV output pressure transducers offering advanced levels of measurement accuracy stability and flexibility from a standard production device.