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Surveyor 4a and Datasonde

Abbreviated Operation Manual

Toolik Lake LTER


For additional information see operations manuals or contact

Chris Crockett@ 508 289 7584

Updates and revisions can be found on the

LTER Arctic Lakes Website

If you have any comments or corrections please let me know


Quick Startup Guide pgs. 2-8

Calibration and Maintenance pgs. 9-14

Surveyor and Datasonde Storage pg. 14

Data download procedure pgs. 15-16











Hydrolab Surveyor and Datasonde 4a Quick Startup Guide

More detailed instructions, troubleshooting, etc see appropriate User Manuals or

Contact Chris Crockett Arctic Lakes RA 508-289-7584


Hydrolab operation is fairly intuitive once you are familiar with the system.  I suggested reading this entire document before operation.


Charging Battery-unit will be sent from Woods Hole with full charge, but may loose some in transit/storage.  If possible I would drain battery and recharge before initial use.  Charging may be necessary after extended use, often best to drain battery by leaving unit on (see below for instructions on how to disable auto Shutdown feature) before recharging.  Extensive testing by George Kling reveals the Hydrolab unit will not function properly if the battery charge is below 7.4Volts.  Note:  Temperatures below 0C will reduce the function time of the unit.

 Charging Procedure

  1. Attach battery charger to main port on surveyor, plug in charger, turn surveyor on (lower right hand button)
  2. You should see a screen indicating CHARGER, VOLTS, ETTC (estimated time till charged), etc.  ETTC will count down as unit is charging, do not stop charging until Charging Complete message is displayed
  3. Typically ETTC indicates about 4 hours till completely charged, usually when possible I let it charge overnight
  4. Surveyor must be left on to charge, you MUST turn power saving auto shutoff feature off, under main menu (use GOBACK to get there if needed)  select SETUP/CAL, SETUP, SURVEYOR, from displayed menu select Timeout: Shutdown, turn option off, this will cause surveyor to stay on indefinitely (if Timeout: Display (i.e. screensaver) option is on surveyor may turn screen off till a button is pressed), Remember to turn Timeout: Shutdown function back on after charging, set to desired amount of time, say 10-15 minutes


Dissolved Oxygen and Depth Calibration

Other calibrations can be done in Woods Hole, but at the beginning of the field season its best to do these at Toolik due to differences in barometric pressure.  Neither procedure takes much time or preparation


Dissolved Oxygen Calibration-see additional calibration and maintenance protocols if

DO membrane needs changing

  1. Connect surveyor and datasonde
  2. Thread DS4 cup and cap (clear storage cup) on end of datasonde
  3. Remove black DS4 cap, Inspect DO membrane (DO sensor has triangle shaped pattern, noticeable under membrane)
  4. Membrane should have no rips, wrinkles, bubbles, etc-if it does then replace
  5. Fill DS4 cup with DI water (or clean tap water), secure cap, shake, rinse, pour out, 2X
  6. Secure sonde upside down with sensors facing towards the ceiling, this can be done using a ring stand, held between your knees, or secured with a bungee cord to a chair turned upside down (my personal favorite), Neil may have a setup for this purpose at Toolik, just take care not to place the weight of the unit on the cable connection at the top (now bottom) of the sonde and make sure its relatively level.
  7. Fill DS4 cup with DI or clean tap water up to (but not over) the O-ring securing the DO membrane
  8. Using the corner of a kimwipe (clean paper towel will work) carefully draw off any water droplets/bubbles on top of the membrane
  9. Place cap on DS4 cup, turn surveyor on (bottom right hand button), and let DO reading settle
  10. Obtain (write down) barometric pressure from Surveyor barometer (you will need this value to calibrate DO and depth), pressure (BP) will likely appear on surveyor screen but if not, it can be added by following directions in the Add and Remove and Parameters section covered later in this guide.
  11. From main menu select SETUP/CAL, CAL, SONDE, choose DO % saturation from list
  12. When prompted enter appropriate barometric pressure for your site, pressure at TFS is fine,

choose DONE

  1. “Calibration successful” or similar message should appear at bottom of surveyor screen
  2. Calibration based on air saturation is complete (this is sufficient).  To calibrate to a water

sample with known DO mg/l, See calibration manual.


Depth Calibration-calibrates depth based on barometric pressure of site

  1. Obtain barometric pressure from Surveyor barometer (you will need this value to calibrate DO and depth), pressure will likely appear on surveyor screen but if not, it can be added by following the Add and Remove and Parameters section covered later in this guide.
  2. From main menu of surveyor with sonde attached, choose SETUP/CAL, CAL, SONDE,

select from menu BP (or similar for barometric pressure), enter value from step one and press


  1. “Calibration successful” or similar message should appear, hit any key to continue
  3. You should end up back on menu which includes BP and DEPTH
  4. Lower the sonde till the SCUFA unit is completely submerged
  5. Select DEPTH25 (may have to choose DEPTH option, then DEPTH25), select DEP25METERS

(or similar), when prompted for zero value enter 0, press DONE

  1. “Calibration successful” or similar message should appear
  2. You’re done with depth calibration, it is a good idea to calibrate for depth at the beginning of every sampling day


Displayed and stored parameters


     The surveyor gives you the option of displaying and storing several different parameters and units of parameters on the surveyor data screen, these will also be the parameters and units stored in memory when creating a data file.  These will not change unless changed by operator, if needed parameters appear on screen, then no modification of parameters is needed.


Parameters Typically Displayed and Stored for Lakes Data

Dep (Depth), Temp, pH, SpC (Sp. Conductance), DO (mg/L), Chl (volts, not in ug/L), PAR, Ref, BP (from Surveyor), Date, Time, Lat/Long, Alt, EBA (Ex. Battery), Cir (circulator on and off. 0 off, 1 on)


Add and Remove and Parameters

1.      You can do this without sonde and datalogger being connected, but if you encounter issues, make sure sonde and datalogger are connected

2.      Turn datalogger on, lower right hand button-Main menu will be displayed with the options SETUP/CAL, GRAPH/TAB, FILES, and STORE

3.      SETUP/CAL select

4.      SETUP select

5.      SRV4A select- (may take a few seconds) a menu will be displayed

6.      Choose the first option Display: Tabular

7.      A menu of all possible parameters/units will be displayed, note our system can’t actually determine all the ones shown.  Use the four-button panel to ADD, REMOVE, the desired parameters.  Note that some parameters cannot be shown simultaneously, for example you can’t display both temp in F and C, depth in feet and meters, etc.

8.      Should see message saying “setup complete” or similar

9.      Choose DONE when finished, hit GO BACK 3x to return to main menu


Datalogging and Field Startup


Procedure assumes calibration and needed maintenance have been performed.  Refer to calibration and maintenance guide for maintenance schedule.


  1. Connect surveyor and datasonde. Take care to ensure male and female adaptors are properly aligned; there will typically be a line or raised dot on the surveyor/ datasonde corresponding to the correct alignment on the other unit.  Don’t “rock” connections together (or apart) or apply unreasonable pressure to the connections-If properly aligned connections should fit with minimal pressure.  If connections are properly aligned, but don’t stay securely connected, this may be due to air trapped when the connections are fitted, make sure this is actually the problem before you apply additional pressure
  2. IMPORTANT-make sure Surveyor and Datasonde are securely connected via black threaded fitting and not simply by the hydrolab cable-datasonde cost about $7000-Also make sure flow through guard is screwed onto the end of the sonde
  3. In similar fashion attach surface LiCor sensor to appropriate cable.  Surface LiCor sensor has typically been house in a modified piece of ubiquitous blue foam, which allows it to float on the surface of the water (see figure below).  Our surface LiCor sensor is submersible, if it slips out of foam it can be retrieved when pulling up the datasonde.  The submersible LiCor cable should already be attached to datasonde, but make sure all connections are secure.  Remember to remove red protective caps on licor sensors before deploying.


                                                                  Kudos to Amanda Floyd for the diagram


  1. Create an appropriate data file for each lake, year
    1. From main menu select FILES, SVR4, CREATE, MANUAL
    2. Using arrow keys print out appropriate file name, typically lake abbreviation and date, select DONE
    3. The parameters menu will appear, if you have already chosen the parameters you would like displayed and stored, then press DONE, otherwise ADD and REMOVE parameters as needed
    4. After you are DONE, a message should appear saying “file created” or similar
    5. You are now prepared to log and store data
  2. Before lowering sonde to desired depth you must, turn on the circulator located at end of the sonde-this feature may be displayed on the surveyor screen, to turn circulator on/off go to SETUP/CAL, SETUP, SONDE, CIR, Cir 0-stirrer off, Cir 1-stirrer on (you should be able to see it circulating).

Note:    circulator ON may not always be necessary

            DO NOT leave circulator ON when not submerged

  1. Lower sonde to desired depth (depth displayed on surveyor) and hold to allow readings to stabilize (about 5-10 seconds)
  2. From main menu (use GO BACK feature if needed), press STORE
  3. Menu displaying created files will appear, find appropriate file for specific lake and date, SELECT (if file not created, refer to appropriate section above)
  4. Top of display will indicate “datalogger active” or similar, the data has now been stored.  Note: do not lower sonde to next depth until you receive “datalogger active” notice
  5. Lower to next depth, stabilize, STORE, files menu should appear with previously used file, press SELECT, repeat as needed
  6. When finished, turn off Circulator, and Surveyor, replace DS4 cup and cap (transparent storage cup and cap) on datasonde, fill cup with about 1inch DI (or temporarily lake water, if DI not available). 
  7. At lab, rinse and store hydrolab with small amount of DI, preferably in dark to help prevent any algal growth on sensors

NOTE: do not allow water in DS4 cup to freeze, and make sure to store surveyor and datasonde in above freezing temps


Major Disaster Prevention

        Make sure Datasonde is secured to cable via threaded collar which screws onto sonde, see that this is tight and secure

        Keep Surveyor secured in boat, do not allow it to submerge and avoid major wettings

        Secure LiCor deck sensor on boat, do not let it submerge

        Remember to place weighted flow through guard on the end of datasonde

        Try to avoid letting datasonde touch benthos

        Store hydrolab in above freezing temps with a small amount of DI to ensure the DO and other membranes do not desiccate

        When calibrating/maintenance etc, be very careful with sensors, wear gloves during maintenance and leave DS4 cup on when moving to prevent damaging sensors, store with small amount of DI in cup.

        Hydrolab will not function properly if the charge is below 7.4 volts



Hydrolab Datasonde 4a Maintenance and Calibration 2003


Maintenance/Calibration Schedule

            Specific Conductance Sensor-clean and calibrate monthly

            pH glass electrode- inspect and calibrate weekly

            pH reference electrode-replace electrolyte and clean membrane weekly

            DO membrane-inspect and calibrate weekly, change membrane monthly

            Depth Sensor-inspect and clean as needed

Lithium batteries/Internal Battery-charge as needed, replace lithiums every 2 years, if surveyor fails to keep track of dates, this may be the problem


DO Membrane

Maintenance Schedule: 

        Inspect and calibrate weekly

        Replace membrane and electrolyte monthly



            New DO membrane and O-Rings

            DO Electrolyte solution, pre-made or 2M KCL

            Curved scissors

            DI water


Membrane Replacement

  1. Remove the O ring around the membrane, if it’s in good shape, firm, not flattened, etc. it can be reused, make sure we have others before you toss it.
  2. Shake, rinse out old electrolyte solution with DI bottle, then lightly rinse with extra KCL
  3. Fill sensor cavity with new electrolyte, sufficient to make perceptible meniscus of solution
  4. Hold new membrane with both hands, ease membrane onto sensor, try not to get any bubbles trapped, if you trap bubbles, try again, filling sensor cavity, getting new membrane as needed.  Tapping can help remove bubbles, but may have to overfill and “slide” bubbles off using forceps or similar before placing membrane down.
  5. Place O ring (new or healthy old one) over gold cathode and try to press down evenly to prevent bubbles or wrinkling.  If you have trapped bubbles or it’s wrinkled, torn, etc start over.
  6. Trim excess membrane using scissors, carefully not to pull, wrinkle membrane
  7. Allow membrane to soak in DI overnight, fill DS4 cap with DI, place cap on, let soak overnight.



DO Calibration-weekly



            Kimwipes, lint free cloth (paper towel will do in a pinch)

            DS4 calibration cup and lid

            DI water, about 500ml



  1. Screw DS4 cap on sonde
  2. Secure datasonde with sensors facing up-a bungee cord, padding, and a stool or chair turned upside down will work if nothing better is available (O ring stand would work)-just don’t let it fall over on its side!
  3. Change membrane if needed, see above
  4. Fill cap with DI/tap water (sp. cond. less than 0.5mS/cm) until the water is just level with the DO membrane O-ring.
  5. Remove water droplets on membrane with lint free cloth, let edge of cloth suck up water, try not to actually touch membrane
  6. Place DS4 lid on, wait a few minutes for DO readings to stabilize, in meantime move to step 7.
  7. Obtain barometric pressure, from Surveyor 4 or other barometer
  8. From opening/main menu of Surveyor 4, choose CALIBRATE/SETUP or similar
  9.  Choose CALIBRATE
  10. Choose SONDE, press once, next menu may take a few seconds to show up
  11. If doing air calibration, choose DO%SAT or similar
  12. You will be asked to enter the barometric pressure; this is best done actually at your site or at a similar barometric pressure.
  13. When finished entering pressure, choose DONE
  14. You should see a message that says calibration complete or similar
  15.  You’re done unless you want to calibrate to a known DO concentration, say from a Winkler or other DO meter, probably a good idea to do air calibration, then see how it compares to Winkler or other DO meter, if its different then you should calibrate with Winkler titration-to calibrate to known DO proceed to step 16
  16. Fill DS4 cup, bucket or similar with enough sample water to submerse DO sensor, don’t forget to put the operating guard back on so you don’t kill the membrane
  17. Let water sit so temp can reach room temp and DO can stabilize, this might take a few hours
  18. Take a sample for Winkler, etc, proceed with Winkler
  19. On Surveyor main menu, choose CALIBRATE/SETUP
  20. Choose CALIBRATE, SONDE, wait for menu, choose OXYGEN, DOmg/L, type in the mg/L value obtained by Winkler of other DO meter, press SELECT/DONE, etc. 
  21. Should see message saying calibration complete or similar



Specific Conductance Sensor

  • Clean and calibrate monthly
  • Housed inside DO sensor housing, about half way up sensor housing


Supplies (maintenance)

            Small bottle brush


            Mild detergent

            Clean water, DI

            Methanol, Isopropyl



  1. Gently scrub sensors with brush/Q-tip and mild detergent
  2. Rinse off soap with clean water
  3. Rub sensors with Q-tip, methanol to further remove any oils
  4. Rinse again with clean water


Check before Calibration (should not change, but good idea to check occasionally)

  1. Make sure sensor operating range is reasonable, go to SETUP, PARAMETERS, SONDE (if needed), SPCONDmS (or us)/cm
  2. You will be prompted to choose a working range, 1. Auto is the default; this allows the multiprobe to adjust automatically to the needed range.  Other options are typically only used for issues relating to resolution/datalogging formats, see manual Abbendum (yellow pages), Rev E, page 6 for more info
  3. SETUP, PARAMETERS, SONDE (if needed), COND, SPCONDms or us/cm
  4. Now prompted to choose function to computer SpCond, Choose FRESHWATER or similar (usually #1), this will correct for temp/matrix issues, etc


Calibration to a Known Standard



            DS4 calibration cup and lid

            DI water

            Conductivity Std, similar uS/cm to sample range

            Kimwipes, lint free cloth, etc


Calibration Procedure

  1. Screw on DS4 calibration cup, fill with DI, place cap on, shake, rinse, repeat
  2. Dry off conductivity cell, no water droplets
  3. CALIBRATE/SETUP, CALIBRATE, SONDE (if needed), COND, choose standard unit, ex SPCONDuS/cm, type in 0, i.e. no conductivity, press DONE/ENTER
  4. You should get calibration complete message, and then returned to the main menu, but you’ve only finished the first calibration
  5. Rinse sensor with small amount of cond. std. twice
  6. Fill cup with cond. std. to the point just above the DO sensor, avoid introducing bubbles into cup by pouring std. down the side of cup (just like it was a heady beer)
  7. Let reading stabilize, go to CALIBRATE/SETUP, CALIBRATE, SONDE (if needed), COND,
  8. Choose same units used for “0” calibration
  9. Type in proper value of std., 1413uS etc
  10. Press enter/DONE
  11. “Calibration complete” message should appear, you are finished with the sp. cond. calibration


You can prepare your own conductivity stds. and DO electrolyte using KCL

KCL molar     Spec. Cond. mS/cm

0.02                                  2.76

0.01                                  1.413

0.005               0.718

0.002               0.292

0.001               0.147

0.0005             0.074




pH Sensor Calibration

            -reference electrode KCl solution should be changed and calibrated weekly

            -glass should be inspected weekly, clean as needed with lint free cloth, take care

             not to scratch glass sensor


Note:  reference electrode differs from that shown in the Datasonde manual.  The reference electrode is the short (4-5cm) sensor typically with a white (or black) plastic cover, when you remove this cover you will see the white electrode membrane underneath.  The glass pH electrode requires little maintenance; simply wipe it off with non-abrasive/low lint cloth (Kimwipe) and methanol as needed.



            PH electrolyte (3M KCl saturated with AgCl)

            Extra O-rings for reference electrode (not needed after every calibration)

            Kimwipes, cotton ball/swab (tissue or paper towel will work in a pinch)

            Methanol (optional)

            DI water

            PH buffer 7

            PH buffer 10, 4, or anything other than 7

                        Note:  buffers can be purchased from Fisher #S71897, S70002 or you can

Purchase dry Metrepak Hydrion Buffer Chemvelopes pH 7 Fisher #14853151C, pH 4 #14853151B, about $9.00 for 5 envelopes, which make 500ml each



1.      Remove white plastic cap on pH sensor, should easily slide off to expose a white membranous electrode-Wear gloves to avoid leaving oils on the sensor

2.      Next you must remove the electrode itself; first you must unscrew the electrode (counterclockwise) and then pull it off.  Note:  sometimes this can prove more difficult than it sounds; once the threads are clear, you are also pulling against a seal formed by two O-rings.

3.      Once the sensor is removed you can now rinse with DI (use wet kimwipe to clean external portion of sensor as needed), rinse with 3M KCL and then refill about with the 3M KCL (labeled as pH electrolyte solution). 

4.      With the hydrolab sensors facing down, screw the sensor back onto the base, this will require a little patience, if too much KCL is in the cap you will not be able to screw it back on.  Once the threads take hold, turn the unit with the sensors facing up and continue to thread the sensor, this allows and air and extra KCl to escape out the membrane.  If done correctly, you should see KCL (and air bubbles) escaping.

5.      Place calibration cap back on datasonde, fill with DI and rinse sensors

6.      Rinse with small amount of pH 7 buffer, secure datasonde with sensors facing up, fill calibration cup with pH 7 buffer, make sure level is above glass pH and reference sensors and plastic cap is removed from reference electrode

7.      Place cap on calibration cup and allow pH. readings to stabilize

8.      On Surveyor, go to CALIBRATION/SETUP, CALIBRATE, SONDE, wait for menu to come up, choose pH

9.      You will be prompted to enter the pH of the buffer solution, make sure to start with the neutral buffer, enter pH value (7), select DONE

10.  Calibration successful message should appear, you must still calibrate with another pH buffer to set the slope of the probe

11.  Rinse sensors with DI and small amount of next buffer (usually 4 or 10)

12.  Fill calibration cup with buffer as noted in step 6

13.  On Surveyor, go to CALIBRATION/SETUP, CALIBRATE, SONDE, wait for menu to come up, choose pH

14.  Enter the value of the pH buffer, i.e. 10 or 4

15.  Calibration successful message should appear

16.  Rinse cup and sensors several times with DI

17.  Fill white plastic sensor cover with DI, invert datasonde (sensors facing down) and place cap on reference sensor

18.  Refill calibration cup with about 2in DI, place cap on and store as needed







Hydrolab Storage Procedure


        Carefully coil cables following the natural tendency of the cable, use twist ties, cable ties, etc to secure cables

        Do not let cables bend over sharp angles or be stored in pinched together

        Store Hydrolab upright, sensors facing down, with DS4 cup filled with about 2 inches of DI water

        End of year storage make sure sensors and DS4 cup and clean, remove DO membrane, DO electrolyte, and pH electrolyte solutions and rinse with DI water





Hydrolab Surveyor 4a Data Download Instructions


-for more in-depth instructions see Surveyor 4a Manual or contact Chris Crockett Arctic Lakes RA

            Note: a second set of download instructions is listed below for older HyperTerminal formats, or if initial set       set of instructions doesn’t produce satisfactory results.


  1. Attach Surveyor 4a and personal computer using the Surveyor to PC adapter (PN 013150)
  2. Turn Surveyor on, a screen with the Hydrolab logo, indicating PC, and the options SETUP/CAL and FILES should appear
  3. Open the HyperTerminal communications program on your PC, if you don’t have this program it can be downloaded free off the Hydrolab web page at Tech Support-Software, or similar programs may work
  4. In HyperTerminal, the Connection Description prompt appears.
  5. Type any name (i.e. Hydrolab), select an icon, and then press OK.
  6. Select the correct communications port (COM1 usually), and press OK.
    The communications port properties opens
  7. Set the properties to:
    Bits per second 19200
    Data bits 8
    Parity none
    Stop bits 1
    Flow control: Xon/Xoff
  8. Press Apply, then OK.
    The HyperTerminal blank screen opens.
  9. Select File and Properties from the HyperTerminal menu.
  10. Select the Settings tab from the Hydrolab Properties screen.
  11. From Settings screen select ASCII setup button (bottom of screen)
  12. ASCII setup window should read ASCII sending:  line delay 0, character delay 0, ASCII receiving: select, wrap lines box, leave others inactivated
  13. Select OK, brings you to setting menu, select OK again
  14. Blank Hyper screen should appear
  15. On Surveyor 4a, select FILES, from menu TRANSMIT, select desired file from menu, choose PRINTER READY format, select stats option (usually NO STATS or DAILY)
  16. Will be prompted “open capture file” (you’ve already done this), “press any key” to continue, download screen will appear on Surveyor, you should see Scan Number increasing, % complete increasing, etc then data should appear on PC Hyper screen.  Large data files may take a while, say 3 minutes/500 scans.  Note: transmitting a file doesn’t remove it from the Surveyor memory
  17. Check to make sure data format looks good, and you have correct file, you can add more files to this page by repeating steps-if format looks wrong you may have to change Delimiter setting on Surveyor (SETUP/CAL, SETUP, choose Radix: Delimiter, etc)
  18. To save data, copy screen (right click, copy, etc) to Word/Notepad, save as TEXT file, it can later be opened in Excel and formatted appropriately-(in Excel, highlight first column, select DATA menu, text to columns, delimited, tab, etc)
  19. To clear Hyper screen, right click mouse, choose Clear Backscroll, screen should clear
  20. I finished, close and disconnect HyperTerminal an turn off Surveyor


Alternate instructions for downloading data using other Hyperterminal formats

Open you communications software (either Hyperterminal if you have windows

95 of Pro comm plus for Dos)  Hyperteminal is located in the program files \

accessories directories.  Procomm is Pcplus\pcplus

The following parameters must be set for downloading using either software

Help commands for both can be found in the Quick reference section of the

Surveyor 4 manual

                        Baud = 19200

                        Data bits = 8

                        Parity = none

                        Stop bits = 1

                        Flow control = Xon / Xoff



Hit the following keys on the Surveyor4:


[Select] Transmit

Select the file you wish to download using the arrow keys and [Select] button

[Select] SS- importable

You will be prompted to hit any key to begin download, prior to hitting any

key name set the default directory and name the file to be downloaded using

the communications software.


In Hyperteminal

Receive the file by hitting [Alt] [t] then [r]

Choose a directory to download the file to

Use Xmodem as the protocol


Name the file to be downloaded.  (no extension, spaces or more than 8




Hit any key on the surveyor to begin downloading file.


Transfer completed message should appear



Please contact with questions, comments, or for technical assistance regarding this web site.