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| SediMeter™ Model 2 specifications, firmware rev. 2
| |
| SM2 versions | SM2A - all operating modes and features SM2N - made for network slave operation |
| Physical | |
| Dimensions | 700 mm x 51 mm (27.6" x 2" - excluding finger screw) |
| Mass | 0.5 kg (1 lb.) |
| Buoyancy in sea water | Will lay down on the bottom |
| Depth rating | 45 m (150') standard |
| Temperature | From 0ºC to 50ºC, not exposed to direct sunlight |
| Sedimeter sensor | |
| Active sensor length | 350 mm (13.8") |
| Detectors per sensor | 36 optical backscatter detectors (OBS) |
| Detector zoning | 6 zones times 6 detectors (this increases the signal-to-noise ratio) |
| Detector spacing | 10 mm |
| Turbidity resolution | 1 FBU (formazin backscatter units, aka FTU) |
| Turbidity accuracy | 6 FBU, estimated |
| Turbidity accuracy in holder | 100 FBU, estimated |
| LED wavelength | 945 nm |
| Visual indicator | A white LED at the top of the sensor blinks once per measurement |
| PCODE | 63682 (turbidity sensor classification in NWIS of USGS) |
| Other sensors | |
| Built-in channels | Temperature (cK, ±0.3 K), battery voltage (mV, ±0.1 V) |
| Optional sensors | 2 channels with signal conditioning (e.g., light, pressure) |
| Logger | |
| Modes | Sleep, stand-alone logger, network slave, network master, USB-network adapter |
| Model | LogDator™ LM-01-00/D, firmware rev. 2 |
| A/D converter | 12-bit resolution in hardware, 16-bit after anti-aliasing |
| Sedimeter channels | 6 analog channels, one for each phototransistor zone |
| Sedimeter sampling | Each LED lits up individually, measures background light and signal |
| Optional sensor sampling | Bursts of 0 to 84 samples at 0.5 Hz to 50 Hz |
| Measurement interval | User selectable from 1 second to 24 hours |
| Real-time clock | UTC (GMT) by default, can be set to within 0.02 s |
| Data records | 512-byte records that include metadata and 16-bit analog data |
| Analog data | Stored in physical units for standard sensors, pressure, and light |
| Conversion and calibration | Built-in calibration values, can be re-calibrated from software |
| Internal memory | 2 MB (4096 records) |
| Memory cards | SD and MMC cards up to 2 GB* |
| User interface | NavPin control stick and 2 x 8 char LCD display* |
| Diver interface | Magnetic switch for mode change and supervision of operation |
| Computer interface | USB* and RS-485 (TIA-485 standard, 9600,N,8,1) |
| Network | Up to 255 units per RS-485 cable |
| Network protocol | LogDator Communication Protocol ver. 2.0 |
| Power supply options | 2 size AA Li batteries 2.1 Ah*, RS-485 cable, USB* (only for set-up and download) |
| Power backup | Keeps settings for up to 30 minutes from 7.2 V |
| Power demand | |
| Input voltage range | 5.5 V < Usupply < 9 V during measurements, 3.5 V < Usupply < 9 V during communication |
| Minimum RAM retention voltage | 1.8 V (lower voltages lead to a Reset) |
| Current use in idle, no card | 34 μA in any mode (with USB disconnected) |
| Current use of memory card | MMC and SD cards typically add some 50 μA when not in use |
| Current drain from supply | Ipeak < 27 mA, Iaverage < 1 mA |
| Multiple power sources at once | The one with the highest voltage is used (battery, USB, or RS-485 cable) |
| Version specific: Model SM2A | |
| Supported features | All those mentioned above |
| Version specific: Model SM2N | |
| Supported features | RS-485, 2 MB memory, network slave mode, cable power** |
| Unsupported features | USB, user interface, memory cards, battery compartment |
| Underwater RS-485 connector | 1 included, a second one optional |
| Power | Supplied via the underwater RS-485 connector |
| Software "sedimeter.exe" | |
| * Features marked with an asterisk only apply to certain models ** SM2N can be used as a stand-alone logger but to re-establish communication one has to reset it by cutting power for >30 minutes | |
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We reserve the right to change specifications and prices without notice, and do not assumte responsibility for typos or other inadvertet errors. Accuracy values refer to one standard deviation and are estimates unless otherwise noted.
