CN0359 4 Wire Conductivity Help

What do the Track-Hold Setup Time and Track-Hold Hold Time settings do? I looked on the wiki, but still did not fully understand. What Excitation voltage/frequency settings would be best for measuring conductivity in the range of 0-200 mS? I am also experiencing an extremely slow response time, especially at higher conductivity levels. The system will reach ~95% of the final value very quickly, but then may take 10+ minutes to reach the final value. Any idea on what could be causing this, or how to get around it?