SBE_38_to_SBE_21_Interface.docx

Part #

Note: Seasave version 7.18 or later also supports acquisition of data from a NMEA device connected directly to computer (instead of deck unit).

See SBE 45 for thermosalinograph without memory or A/D auxiliary sensor channels.

SBE 21 Auxiliary A/D Channel Configuration Selections -- MUST SELECT ONE

· 21-1a provides 1 bulkhead connector for 4 single-ended A/D channels. Single-ended channels are acceptable for sensors that draw very little current & can share power & signal common with SBE 21 without injecting ground line noise into signal.

· 21-1b provides 1 bulkhead connector for 2 differential A/D channels (can also be used with 2 single-ended A/D sensors). Sensors that draw larger amounts of current generate ground line noise which interferes with signals. For these sensors, when power & signal common are shared, a differential channel is needed. Differential input amplifiers are able to distinguish & reject noise from signal.

Note: 21-1a & -1b do not include auxiliary sensors, mounts, or interface cables.

Many auxiliary sensors are electrically compatible with SBE 21; these sensors can be purchased from Sea-Bird & integrated with SBE 21 at our factory, or you can purchase cables from Sea-Bird & perform integration yourself. Note that integration of these sensors at Sea-Bird is limited to providing appropriate cable & setting up instrument configuration file. Sea-Bird does not provide methods for mechanical integration of these auxiliary sensors with SBE 21. User must design / provide flow-through chamber that receives outflow from SBE 21 for auxiliary sensors.

· See Third Party portion of price list for ordering details on fluorometers, transmissometers, turbidity meters, etc. that are electrically compatible with SBE 21. These sensors can be purchased from Sea-Bird, along with appropriate cables. Alternatively, you can purchase sensors from third party manufacturers, & purchase cables from Sea-Bird.

User can change sensors on SBE 21 in field, if combination is compatible with auxiliary A/D channel configuration selection. However, bulkhead connector requires Y-cable to connect multiple auxiliary sensors to SBE 21; each Y-cable is unique to sensors being integrated, so changing sensors may require changing Y-cable.

SBE 21 Remote Sea Surface Thermometer Option

· Some custom SBE 21s with serial number less than 3345 & greater than 3110, & all standard SBE 21s with serial number less than 3110, supported input from remote SBE 3 temperature sensor through a 3-pin remote temperature connector.Current SBE 21 electronics does not support SBE 3 as remote temperature sensor.

Shown below is SBE 38 installed in 50244 mounting kit; see document 67071.

SBE 21 Accessories

· PN 17015 -- AC power cable

· PN 80438 (DN 31063) -- 10 m cable for connection to SBE 21

· PN 17031 (DN 30581) -- 2.4 m pigtail cable for connection to SBE 21

· PN 801424 (DN 32787) -- 1.8 m NMEA test cable for connection to computer simulating NMEA input for testing NMEA interface. NMEA simulation program, NMEATest, is part of Seasoft software, & is installed when you install SBE Data Processing.

· PN 171887 (DN 32431) -- 3 m cable for connection to computer

· PN 171888 -- Cable adapter, DB-25S to DB-9P (for use with computer with DB-25 connector)

· PN 50368 -- connector assembly for 4-pin SeaCAT Data I/O (for connection to SBE 21)

· PN 50369 -- connector assembly for 5-pin NMEA Input (for connection to NMEA device -- can acquire latitude/longitude & depth data)

Note: Order 50107 instead of 50298 for use with SBE 21 that has 3-pin bulkhead connector for remote temperature input -- compatible withSBE 3 Temperature Sensor. All standard SBE 21s with serial number less than 3110 & some custom SBE 21s with serial number less than 3345 & greater than 3110 are compatible with SBE 3 Temperature Sensor. See document 67060 for complete listing of parts.

slide Tygon on end of conductivity cell

50315 provides fittings (2) to hold AF24173 Anti-Foulant Devices at each end of conductivity cell. See Application Note 70: Installing Anti-Foulant Device Mount Kit on SBE 4, 16, 19, and 21 Conductivity Cells.

· SBE 21s shipped before 2002 used a smaller anti-foulant device inside Tygon tubing that attached to end of conductivity cell, & did not include 50315. For those SBE 21s, order 50315 & 801542 AF24173 Anti-Foulant Devices first time you need new Anti-Foulant Devices. Once you have 50315, order AF24173 Anti-Foulant Devices as needed.

· SBE 21s shipped after 2002 include 50315 & 801542 installed on SBE 21. Order AF24173 Anti-Foulant Devices as needed.

Note: Order PN 90387.1 instead for use with older SBE 21 that is compatible with SBE 3 Temperature Sensor -- supports input from remote SBE 3 thermometer through 3-pin remote temperature connector.

image3.jpeg image4.jpeg image5.jpeg image6.jpeg image7.jpeg image8.jpeg image9.jpeg image1.gif image2.jpeg