The purpose of the MIDAS BathyPack is to convert pressure measurements into depth data, taking into account local variations in water density to ensure the highest possible accuracy. In addition, the MIDAS BathyPack accepts data from an altimeter to provide height above the seabed, corrected using the on-board Valeport “time of flight” sound velocity sensor, thus giving an overall location of the device within the water column. Whilst the concept of such a bathymetry system is not new, the MIDAS BathyPack builds on the standard specification you would expect with several unique features that significantly enhance the performance of the product:
• Temperature compensated piezo-resistive pressure sensor gives ±0.01% accuracy with better stability and durability than a resonant quartz type. In addition, there is no oil reservoir to protect the sensor, allowing easier maintenance and faster deployment.
• Valeport’s own inductive coil conductivity sensor is constructed from advanced composite materials to eliminate the effects of pressure on sensor performance. Most inductive cells distort under pressure, giving errors in the measurement – even a few μm is enough to put the sensor out of specification at depth. This cell has no such errors. Inductive cells also have an advantage over electrode conductivity sensors, in that they are less susceptible to contamination by oil, growth or debris.
• Full “in situ” factory calibration; inductive conductivity cells are affected by the presence of any object (conductive or non-conductive) that lies within the sensor’s field (within approx. 5cm). Valeport’s factory calibration against a salinometer, performed with all other sensors and guard in close proximity, guarantees in-field accuracy. A simple “resistor calibration” actually does nothing more than verify sensor operation. Further, the digital measurement technique virtually eliminates drift in sensor calibration, eliminating the need for “field calibration” procedures.
• Unique “synchronised sampling” means that all sensors are sampled at precisely the same instant, not in sequence. This removes alias errors from the measurements.
• Altimeter input fitted as standard; no need for upgrades – just plug in the sensor.
• Titanium housing as standard; no corrosion issues, and a maximum depth rating of 6000m. Note that a selection of pressure sensor ranges is available, so your instrument’s depth rating may be limited to less than the full 6000m.
• Full UNESCO depth calculation for more accurate depth measurement; the system uses the standard UNESCO method of integrating the water density variations to calculate the depth from pressure, not the simplified method of just averaging the density.
• All data is viewed and stored on a topside PC, so no dedicated control unit is required. The intuitive BathyLog software allows you to setup the BathyPack, log all incoming data, and display and graph the data in real time.
• BathyLog also accepts data from Valeport’s Modus IPS and miniIPS pressure sensors, applying the BathyPack’s density profile to provide an accurate pressure / depth conversion for separate devices in the same locality.
In summary, the MIDAS BathyPack sets out to demystify the accurate calculation of depth from water pressure; state of the art sensing technology gives you accurate data; precise calculations give you accurate answers; simple PC software gives you total control. Getting the right answer has never been easier.
Ordering Information:
0608002 MIDAS BathyPack in titanium housing, fitted with 0.01% piezo-resistive pressure sensor ( standard ranges are 10, 30, 100 300 & 600 bar ), fast response PRT temperature sensor, pressure compensated conductivity cell and a 50mm path length sound velocity sensor. Includes 6 way MCBHF for interface to customer altimeter and 0.5m pigtail. Supplied with BathyLog display and logging Windows software, 3m interface lead, operating manual and transit case.
Note: Altimeter NOT included.
Associated Products
0760001 MiniIPS Pressure Sensor (add as an option if multiple depth references are required )
0608003 19″ rack mount touch screen data display & logging unit
0608004 8 channel USB / serial interface unit
Components and Spares
0400EA11 Pigtail 50cm – Male Line 10 pin Subconn with sleeve, for connection to instrument. (Subconn parts MCIL10M and NSW DLSA-M)
0400EA13 Titanium Subconn bulkhead connector with sleeve for titanium housed instrument. (Subconn parts MCBH10F & NSW DLSA-F. Specify Titanium)
0400EA18 Brass Subconn bulkhead connector with sleeve for acetal housed instrument. (Subconn parts MCBH10F & NSW DLSA-F. Specify Brass)
TKBATHY Tool Kit
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