Some of your answers:
How frequently must it be calibrated
Frequent calibration is recommended. Fresh calibration fluids should be used when old fluid becomes contaminated.
How is it calibrated, is solution provided?
Looks like a 100 and 1000 ppm solution is provided.
How often must the probe be replaced?
Per instructions, every 18-24 mnths.
What is the accuracy +/-?
What is the precision? 100s 10s 1s .1s?
Resolution: 000.2 ppm
Accuracy: +/- 2% of the reading after calibration
Can the monitor run submersed 24/7 or is it only for intermittant testing?
Looks similar to the pH montior--both, but must be capped if stored.
Here's the link:
User guide