Portasal salinometer protocol (used on Troll transect cruises)#

From notes by Tore Hatterman

Collecting samples for the salinometer#

  • Niskins: averaging over 5 m

  • Sample every 1000m over deep stations, at beginning of every section, quality control

  • Ship takes bottom water samples

  • Rinse bottles prior to use warm but, not too hot (inner coating)

  • Sampling with rinsing three times

  • Dry with lab towel top before putting insert and lid

  • No massive rush to get screw taps on

  • Leave 24h in room where sainometer is for temp stabilization (process one crate at a time, not bottle by bottle)

  • Paul recommends to use our instrument, optimare can be fishy, becasue its all automatic

Practical#

  1. Fill distilled water (air vent on, without pressure)

  2. Leave tank overflow vent open, open drain cell

  3. Strap down properly

  4. Turn on (swicth on the back)

  5. Measure temp in room and set bath temp (Tset) 2 deg above that

    • Range of bath: [1 deg below room, 2 deg above]

  6. Wait 6 hour or so to equillibriate

  7. Power up pump, 1-3 pumping speed (2)

  8. Probably massage peristiotic pump tube

  9. Flush a few 100ml with distilled water

Do this at the beginning of the cruise and then ready sampling procedure:

Sampling procedure#

  1. Take stabilized crate

  2. Shake bottles slightly

  3. Logsheet (from Paul)

  4. Log standard sample sal & cond

  5. Log defined bath temp, not actual and log air temp

  6. Make sure that no distilled water from the pipe drains into the sample bottle

  7. Use air pump to first blow out old stuff and then flush new sample water into the system (3 times)

  8. On 3rd sample, turn fucntion knob from standby to read to pass the water into the wheatstone bridge

  9. Make sure to bypass/ put back to standby when samples put back to not upset the electronics

  10. Repeat to take 3 independent samples

  11. Take new (not evaporated) standard of same value

  12. Fill with distilled water at the end of the sampling, ready for next round

  13. Empty cell and tank completely at end of cruise to avoid freezeup

Troubleshooting#

If not working: Stop, put lots of distilled water through it, rinse with distilled water to resolve stuff a crate is about 45min